They further suggest that this division corresponds to a distinction between episodic and recognition memory. The perirhinal cortex Abstract Anatomically, the perirhinal cortex sits at the boundary between the medial temporal lobe and the ventral visual pathway. The perirhinal cortex is part of the parahippocampal PERIRHINAL CORTEX (PRC): PRC functions. . TE1. .
A predominant view of perirhinal cortex (PRC) and postrhinal/parahippocampal cortex (POR/PHC) function contends that these structures are tuned to represent objects and spatial information, respectively. In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary Continue reading
Perirhinal cortex is importantly involved in a number of different memory functions. Five of the models address recognition memory function (Sohal and Hasselmo .
These functions include roles in perception, particularly for object-related information, and in memory, notably but not exclusively, recognition memory and paired associate learning. Aggleton & Brown argue that the function of the hippocampus and perirhinal cortex can be dissociated along a spatial/nonspatial dimension.
Perirhinal Cortex and Associated Cortical AreasResearch on learning and memory has confirmed that the structures within the hippocampal formation, including the dentate gyrus, Ammon's horn, and the subiculum play an important role in certain kinds of memory.
Instead, it was designed to investigate whether the shape of the functions re-lating activity in hippocampus and perirhinal cortex to memory strength might differ in a specic way. However, the findings from previous studies that examined the effects of perirhinal cortex damage on spatial memory Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. perirhinal cortex, and, notwithstanding the difficulty of 142 Perceptual-mnemonic functions of the perirhinal cortex Elisabeth A. Murray and Timothy J. Bussey It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys.
Both of these studies, however, were based on areal boundaries that have now undergone revision. To inhibit neuronal activity in the hippocampus and perirhinal cortex, a glass pipette was filled with lidocaine (AlleMan Pharma; 1%, w/v) and inserted into the ipsilateral hippocampus or perirhinal cortex on the basis of stereotaxic coordinates (53, 54). and Bussey, T.J. (1999) Perceptual-mnemonic functions of the perirhinal cortex. Impairments in visual discrimination after perirhinal cortex lesions: Testing 'declarative' vs. 'perceptual-mnemonic' views of perirhinal cortex function. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Impairments in visual discrimination after perirhinal cortex lesions, testing 'declarative' vs. 'perceptual-mnemonic' views of perirhinal cortex function. The testing of these opposing views of perirhinal cortex function has been hampered by the fact that in humans, lesions including the perirhinal cortex typically encompass large expanses of the anterior and anteromedial temporal lobe, such that the precise neuroanatomical locus of the functional impairments is difficult to determine.
However, a thorough characterization of the specificity and efficiency of the PV-IRES-Cre line in perirhinal cortex is still missing. One major set of MTL projections to the perirhinal cortex that tends to be overlooked in con-sidering the functions of the perirhinal cortex is its prominent interconnections with the amygdala (Stefanacci et al. Alert. It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys. . Damage to PRC results in deficits in complex visual discrimination [36], object recognitionmemory [37,38], and attention to visual stimuli [39]. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. The rhinal cortex is divided into the entorhinal (ERC) and perirhinal cortices (PRC), which serve as the major cortical communication relays for the hippocampus.
In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary tangle pathology [1], which is closely linked to neural injury in AD. Perirhinal cortex is a cortical region in the medial temporal lobe that is made up of Brodmann areas 35 and 36. Contrasting hippocampal, perirhinal cortex function using imme-diate early gene imaging. The EC is the main interface between the hippocampus and neocortex. by neurons in perirhinal cortex. Whereas the perirhinal cortex appears to support short-term memory for novel object information (Brown and Aggleton, 2001), neuropsychological evidence suggests that the hippocampus is critical when associative information is involved (for review, see Jonides et al., 2008), in line with its proposed function as a relational binder in long-term . The perirhinal cortex (Brodmann's area 35) is a multimodal area that is important for normal memory func-tion. These studies highlighted the low density of PV-INs in associative cortices, including the perirhinal cortex. The hippocampus and perirhinal cortex (PRC) are two possible regions involved in discriminating similar stimuli and forming distinctive memory representations. I review seven models of the contribution of perirhinal cortex (PRC) or neighboring neocortical regions to cognition. Functional double dissociation between two inferior temporal cortical areas: perirhinal cortex versus middle temporal gyrus. It is highly connected to other brain structures. In this study, 28 participants (15 males) were scanned using high-resolution fMRI when a picture (e.g., a dog) was paired with the same picture, with a similar picture of the same . We recently proposed that the perirhinal cortex in the rat be divided into two regions: a rostral region that bears cytoarchitec-tonic and connectional similarities to the monkey perirhi- 3. Thirdly, we review the main functions of the perirhinal cortex; its roles in perception, recognition memory, spatial and contextual memory and fear conditioning are explored. 35, 4350-4365 2 Murray, E.A. The present experiment tested predictions of a 'perceptual-mnemonic/feature conjunction' (PMFC) model of perirhinal cortex function. Brain regions and Object Identification Area 36 is sometimes divided into three subdivisions: 36d is the most rostral and dorsal, 36r ventral and caudal, and 36c the most caudal. The perirhinal cortex and hippocampus have close anatomical links, and it might, therefore, be predicted that they have close, interlinked roles in memory. 1987; McIntyre et al. The current study also found that FC was decreased in some brain regions of children with ASD, including the hippocampus, parahippocampal gyrus, superior frontal gyrus, inferior temporal gyrus, precuneus, amygdala, and perirhinal cortex of the talar fissure, with the hippocampus and parahippocampal gyrus predominating. 1996). 77: 587-598, 1997. Whether or not advanced age affects the ability of PRC principal cells to support these dual roles, however . J. Neurosci. It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys. Information flow from the rhinal cortex, through the hippocampus, and back to the rhinal cortex is a perfect example of a reverberatory, Hebbian cell assembly. Particular attention is paid the anatomical and electrophysiological properties of these projections. 38).
Such a nding would provide an alternative view of the fMRI activity that has often Entorhinal cortex visible at near bottom. Save. The human perirhinal cortex (PRC) plays critical roles in episodic and semantic memory and visual perception. The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. Sci. The evidence suggests that .
These cognitive processes are required for recognition memory, which declines during normal aging. Function. Reducing perceptual interference improves visual discrimination in mild cognitive impairment: Implications for a model of perirhinal cortex function By Rachel Newsome and Audrey Duarte The effects of selective hippocampal damage on tests of oddity in rhesus macaques Notably, rats with hippo-campal lesions exhibited the same impairment. B, Comparative and Physiological Psychology, 58 (3-4), 202-217. The perirhinal cortex sends projections to the lateral entorhinal cortex (LEC). inputs to the rat perirhinal cortex (Deacon et al., 1983). (2001) J Comput Neurosci 10:5-23; Bogacz and Brown (2003a) Neurocomputing 52:1-6; Norman and O'Reilly (2003) Psychol Rev 110:611-646; Cowell et al.
This function of the perirhinal cortex and its sensitivity to semantic variables shown here, together with the connectivity findings reviewed in the Discussion, suggest that it integrates perceptual feature information into higher-level, semantic memories of meaningful objects (refs.18 and 37; see also ref. Eur.
The perirhinal cortex also sends projections to the nucleus accumbens (NAc) (Christie et al. Area 36 is six-layered, dysgranular cortex . I review seven models of the contribution of perirhinal cortex (PRC) or neighboring neocortical regions to cognition. Journal of Neuroscience.
This denition is neutral as to For example, removal of the perirhinal cortex yields severe impairments on tests of stimulus recognition and stimulus-stimulus a The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. It has prominent interconnections not only with both these systems, but also with a wide range of unimodal and polymodal association areas.
aimed at providing a fundamental understanding of how the orbitofrontal cortex actually functions, and thus in how it is involved in motivational behavior such as feeding and drinking, in emotional behavior, and in social behavior. J. Neurophysiol.
TEa. Trends Cogn.
Buckley, M. J., D. Gaffan, and E. A. Murray. E1020-E1027, 10.1073/pnas.1419649112. The drug (150 nl) was injected by a gentle pressure at least 20 min before the training onset. It receives highly-processed sensory information from all sensory regions, and is generally accepted to be an important region for memory.It is bordered caudally by postrhinal cortex or parahippocampal cortex (homologous . The perirhinal cortex is a polymodal association area that contributes importantly to normal recognition memory. The PRC consists of Brodmann areas 35 and 36 (BA35, BA36). In addition, the neuroanatomy and neurophysiology of rat PRC have been described in considerable detail at the cellular and systems levels. A new view of perirhinal cortex function is proposed, one that does not assume strict modularity of function in the occipito-temporal visual stream, but replaces this idea with the notion of a hierarchical representational continuum. Proceedings of the National Academy of Sciences, 112 (2015), pp. Quarterly Journal of Experimental Psychology 58B, 218 - 233 . Dual functions of perirhinal cortex in fear conditioning Abstract The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. function are dependent upon input from the perirhinal cortex. 195. Hippocampus 17, 709-722 4
It has prominent interconnections not only with both these systems, but also with a wide range of unimodal and polymodal association areas. Numerous studies support the importance of the perirhinal cortex (PRC) and parahippocampal cortex (PHC) in episodic memory. The perirhinal cortex is a polymodal association area that contributes importantly to normal recognition memory. The entorhinal cortex ( EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time. tion that a model may take is that cognitive functions are not localized, but rather that a cognitive goal such as recognition memory can be carried out in many regions, such as PRC, an-terior IT, or hippocampus. (2006) J . The perirhinal cortex plays an important role in object recognition and in storing information (memories) about objects. 2007; 27:2548-2559. hippocampus and perirhinal cortex, respectively. The perirhinal cortex is composed of two regions: areas 36 and 35. The perirhinal cortex (PRC) is proposed to both represent high-order sensory information and maintain those representations across delays. Related Content 1195. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. The perirhinal cortex was divided into areas 35 and 36, and the postrhinal cortex was divided into dorsal (PORd) and ventral (PORv) subregions. . There is considerable disagreement, however, about the most accurate way to . First, the MTL is not exclusively involved in mnemonic processes; some MTL structures, most notably the perirhinal cortex, also contribute to perception. At the cellular level, PRC neurons Bartko SJ, Winters BD, Cowell RA, Saksida LM, Bussey TJ. Given the strong projections linking these two structures, it is logical to predict that spatial memory abilities would be impaired after perirhinal cortex lesions. European Journal of Neuroscience 17, 649 - 660 . Second, there are some forms of memory, including recognition memory, that are not always affected by selective hippocampal lesions. A convergence of recent findings from lesion and electrophysiological studies has provided new evidence that this area participates in an even broader range of memory functions than previ However, functional evidence supporting the relationship between the meth-induced memory deficits and relapse is lacking. It is closely interconnected with divergent unimodal and polymodal association area of the neocortex as well as with the hippocampal . The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. Perirhinal-LEC-hippocampus.
The importance of medial temporal lobe (MTL) structures (i.e., the perirhinal, entorhinal, and parahippocampal cortices and the hippocampus) for memory has been established in humans, monkeys, and rodents (Squire and Zola-Morgan 1991; Eichenbaum and Cohen 2001).The pattern of impaired and spared functions after damage to the MTL has been described since early studies of patient H.M . Lesions to the perirhinal cortex in both monkeys and rats lead to the impairment of visual recognition memory, disrupting stimulus-stimulus associations and object-recognition abilities. Area 36 is sometimes divided into three subdivisions: 36d is the most rostral and dorsal, 36r ventral and caudal, and 36c the most caudal. After some background anatomical information, a summary is given of the results of ablation experiments that indicate the functions of perirhinal cortex. Perceptual functions of perirhinal cortex in rats: zero-delay object recognition and simultaneous oddity discriminations.
A predominant view of perirhinal cortex (PRC) and postrhinal/parahippocampal cortex (POR/PHC) function contends that these structures are tuned to represent objects and spatial information, respectively. In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary Continue reading
Perirhinal cortex is importantly involved in a number of different memory functions. Five of the models address recognition memory function (Sohal and Hasselmo .
These functions include roles in perception, particularly for object-related information, and in memory, notably but not exclusively, recognition memory and paired associate learning. Aggleton & Brown argue that the function of the hippocampus and perirhinal cortex can be dissociated along a spatial/nonspatial dimension.
Perirhinal Cortex and Associated Cortical AreasResearch on learning and memory has confirmed that the structures within the hippocampal formation, including the dentate gyrus, Ammon's horn, and the subiculum play an important role in certain kinds of memory.
Instead, it was designed to investigate whether the shape of the functions re-lating activity in hippocampus and perirhinal cortex to memory strength might differ in a specic way. However, the findings from previous studies that examined the effects of perirhinal cortex damage on spatial memory Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. perirhinal cortex, and, notwithstanding the difficulty of 142 Perceptual-mnemonic functions of the perirhinal cortex Elisabeth A. Murray and Timothy J. Bussey It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys.
Both of these studies, however, were based on areal boundaries that have now undergone revision. To inhibit neuronal activity in the hippocampus and perirhinal cortex, a glass pipette was filled with lidocaine (AlleMan Pharma; 1%, w/v) and inserted into the ipsilateral hippocampus or perirhinal cortex on the basis of stereotaxic coordinates (53, 54). and Bussey, T.J. (1999) Perceptual-mnemonic functions of the perirhinal cortex. Impairments in visual discrimination after perirhinal cortex lesions: Testing 'declarative' vs. 'perceptual-mnemonic' views of perirhinal cortex function. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Impairments in visual discrimination after perirhinal cortex lesions, testing 'declarative' vs. 'perceptual-mnemonic' views of perirhinal cortex function. The testing of these opposing views of perirhinal cortex function has been hampered by the fact that in humans, lesions including the perirhinal cortex typically encompass large expanses of the anterior and anteromedial temporal lobe, such that the precise neuroanatomical locus of the functional impairments is difficult to determine.
However, a thorough characterization of the specificity and efficiency of the PV-IRES-Cre line in perirhinal cortex is still missing. One major set of MTL projections to the perirhinal cortex that tends to be overlooked in con-sidering the functions of the perirhinal cortex is its prominent interconnections with the amygdala (Stefanacci et al. Alert. It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys. . Damage to PRC results in deficits in complex visual discrimination [36], object recognitionmemory [37,38], and attention to visual stimuli [39]. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. The rhinal cortex is divided into the entorhinal (ERC) and perirhinal cortices (PRC), which serve as the major cortical communication relays for the hippocampus.
In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary tangle pathology [1], which is closely linked to neural injury in AD. Perirhinal cortex is a cortical region in the medial temporal lobe that is made up of Brodmann areas 35 and 36. Contrasting hippocampal, perirhinal cortex function using imme-diate early gene imaging. The EC is the main interface between the hippocampus and neocortex. by neurons in perirhinal cortex. Whereas the perirhinal cortex appears to support short-term memory for novel object information (Brown and Aggleton, 2001), neuropsychological evidence suggests that the hippocampus is critical when associative information is involved (for review, see Jonides et al., 2008), in line with its proposed function as a relational binder in long-term . The perirhinal cortex (Brodmann's area 35) is a multimodal area that is important for normal memory func-tion. These studies highlighted the low density of PV-INs in associative cortices, including the perirhinal cortex. The hippocampus and perirhinal cortex (PRC) are two possible regions involved in discriminating similar stimuli and forming distinctive memory representations. I review seven models of the contribution of perirhinal cortex (PRC) or neighboring neocortical regions to cognition. Functional double dissociation between two inferior temporal cortical areas: perirhinal cortex versus middle temporal gyrus. It is highly connected to other brain structures. In this study, 28 participants (15 males) were scanned using high-resolution fMRI when a picture (e.g., a dog) was paired with the same picture, with a similar picture of the same . We recently proposed that the perirhinal cortex in the rat be divided into two regions: a rostral region that bears cytoarchitec-tonic and connectional similarities to the monkey perirhi- 3. Thirdly, we review the main functions of the perirhinal cortex; its roles in perception, recognition memory, spatial and contextual memory and fear conditioning are explored. 35, 4350-4365 2 Murray, E.A. The present experiment tested predictions of a 'perceptual-mnemonic/feature conjunction' (PMFC) model of perirhinal cortex function. Brain regions and Object Identification Area 36 is sometimes divided into three subdivisions: 36d is the most rostral and dorsal, 36r ventral and caudal, and 36c the most caudal. The perirhinal cortex and hippocampus have close anatomical links, and it might, therefore, be predicted that they have close, interlinked roles in memory. 1987; McIntyre et al. The current study also found that FC was decreased in some brain regions of children with ASD, including the hippocampus, parahippocampal gyrus, superior frontal gyrus, inferior temporal gyrus, precuneus, amygdala, and perirhinal cortex of the talar fissure, with the hippocampus and parahippocampal gyrus predominating. 1996). 77: 587-598, 1997. Whether or not advanced age affects the ability of PRC principal cells to support these dual roles, however . J. Neurosci. It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys. Information flow from the rhinal cortex, through the hippocampus, and back to the rhinal cortex is a perfect example of a reverberatory, Hebbian cell assembly. Particular attention is paid the anatomical and electrophysiological properties of these projections. 38).
Such a nding would provide an alternative view of the fMRI activity that has often Entorhinal cortex visible at near bottom. Save. The human perirhinal cortex (PRC) plays critical roles in episodic and semantic memory and visual perception. The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. Sci. The evidence suggests that .
These cognitive processes are required for recognition memory, which declines during normal aging. Function. Reducing perceptual interference improves visual discrimination in mild cognitive impairment: Implications for a model of perirhinal cortex function By Rachel Newsome and Audrey Duarte The effects of selective hippocampal damage on tests of oddity in rhesus macaques Notably, rats with hippo-campal lesions exhibited the same impairment. B, Comparative and Physiological Psychology, 58 (3-4), 202-217. The perirhinal cortex sends projections to the lateral entorhinal cortex (LEC). inputs to the rat perirhinal cortex (Deacon et al., 1983). (2001) J Comput Neurosci 10:5-23; Bogacz and Brown (2003a) Neurocomputing 52:1-6; Norman and O'Reilly (2003) Psychol Rev 110:611-646; Cowell et al.
This function of the perirhinal cortex and its sensitivity to semantic variables shown here, together with the connectivity findings reviewed in the Discussion, suggest that it integrates perceptual feature information into higher-level, semantic memories of meaningful objects (refs.18 and 37; see also ref. Eur.
The perirhinal cortex also sends projections to the nucleus accumbens (NAc) (Christie et al. Area 36 is six-layered, dysgranular cortex . I review seven models of the contribution of perirhinal cortex (PRC) or neighboring neocortical regions to cognition. Journal of Neuroscience.
This denition is neutral as to For example, removal of the perirhinal cortex yields severe impairments on tests of stimulus recognition and stimulus-stimulus a The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. It has prominent interconnections not only with both these systems, but also with a wide range of unimodal and polymodal association areas.
aimed at providing a fundamental understanding of how the orbitofrontal cortex actually functions, and thus in how it is involved in motivational behavior such as feeding and drinking, in emotional behavior, and in social behavior. J. Neurophysiol.
TEa. Trends Cogn.
Buckley, M. J., D. Gaffan, and E. A. Murray. E1020-E1027, 10.1073/pnas.1419649112. The drug (150 nl) was injected by a gentle pressure at least 20 min before the training onset. It receives highly-processed sensory information from all sensory regions, and is generally accepted to be an important region for memory.It is bordered caudally by postrhinal cortex or parahippocampal cortex (homologous . The perirhinal cortex is a polymodal association area that contributes importantly to normal recognition memory. The PRC consists of Brodmann areas 35 and 36 (BA35, BA36). In addition, the neuroanatomy and neurophysiology of rat PRC have been described in considerable detail at the cellular and systems levels. A new view of perirhinal cortex function is proposed, one that does not assume strict modularity of function in the occipito-temporal visual stream, but replaces this idea with the notion of a hierarchical representational continuum. Proceedings of the National Academy of Sciences, 112 (2015), pp. Quarterly Journal of Experimental Psychology 58B, 218 - 233 . Dual functions of perirhinal cortex in fear conditioning Abstract The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. function are dependent upon input from the perirhinal cortex. 195. Hippocampus 17, 709-722 4
It has prominent interconnections not only with both these systems, but also with a wide range of unimodal and polymodal association areas. Numerous studies support the importance of the perirhinal cortex (PRC) and parahippocampal cortex (PHC) in episodic memory. The perirhinal cortex is a polymodal association area that contributes importantly to normal recognition memory. The entorhinal cortex ( EC) is an area of the brain's allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time. tion that a model may take is that cognitive functions are not localized, but rather that a cognitive goal such as recognition memory can be carried out in many regions, such as PRC, an-terior IT, or hippocampus. (2006) J . The perirhinal cortex plays an important role in object recognition and in storing information (memories) about objects. 2007; 27:2548-2559. hippocampus and perirhinal cortex, respectively. The perirhinal cortex is composed of two regions: areas 36 and 35. The perirhinal cortex (PRC) is proposed to both represent high-order sensory information and maintain those representations across delays. Related Content 1195. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. The perirhinal cortex was divided into areas 35 and 36, and the postrhinal cortex was divided into dorsal (PORd) and ventral (PORv) subregions. . There is considerable disagreement, however, about the most accurate way to . First, the MTL is not exclusively involved in mnemonic processes; some MTL structures, most notably the perirhinal cortex, also contribute to perception. At the cellular level, PRC neurons Bartko SJ, Winters BD, Cowell RA, Saksida LM, Bussey TJ. Given the strong projections linking these two structures, it is logical to predict that spatial memory abilities would be impaired after perirhinal cortex lesions. European Journal of Neuroscience 17, 649 - 660 . Second, there are some forms of memory, including recognition memory, that are not always affected by selective hippocampal lesions. A convergence of recent findings from lesion and electrophysiological studies has provided new evidence that this area participates in an even broader range of memory functions than previ However, functional evidence supporting the relationship between the meth-induced memory deficits and relapse is lacking. It is closely interconnected with divergent unimodal and polymodal association area of the neocortex as well as with the hippocampal . The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. Perirhinal-LEC-hippocampus.
The importance of medial temporal lobe (MTL) structures (i.e., the perirhinal, entorhinal, and parahippocampal cortices and the hippocampus) for memory has been established in humans, monkeys, and rodents (Squire and Zola-Morgan 1991; Eichenbaum and Cohen 2001).The pattern of impaired and spared functions after damage to the MTL has been described since early studies of patient H.M . Lesions to the perirhinal cortex in both monkeys and rats lead to the impairment of visual recognition memory, disrupting stimulus-stimulus associations and object-recognition abilities. Area 36 is sometimes divided into three subdivisions: 36d is the most rostral and dorsal, 36r ventral and caudal, and 36c the most caudal. After some background anatomical information, a summary is given of the results of ablation experiments that indicate the functions of perirhinal cortex. Perceptual functions of perirhinal cortex in rats: zero-delay object recognition and simultaneous oddity discriminations.