Abstract
Neurophysiological studies in nonhuman primates have demonstrated that the prefrontal cortex (PFC) plays a critical role in the acquisition of learned categories following training. What is presently unclear is whether this cortical area also plays a role in spontaneous recognition and discrimination of natural categories. Here, we explore this possibility by recording from neurons in the PFC while rhesus listen to species-specific vocalizations that vary in terms of their social function and acoustic morphology. We found that ventral prefrontal cortex (vPFC) activity, on average, did not differentiate between food calls that were associated with the same functional category, despite having different acoustic properties. In contrast, vPFC activity differentiated between food calls associated with different functional classes and specifically, information about the quality and motivational value of the food. These results suggest that the vPFC is involved in the categorization of socially meaningful signals, thereby both extending its previously conceived role in the acquisition of learned categories and showing the significance of using natural categorical distinctions in the study of neural mechanisms.
Highlights
Categorization is a natural and adaptive process seen in all animals
The relationship between the ‘‘repeated’’ and test exemplar was varied so that we could test whether ventral prefrontal cortex (vPFC) neurons code transitions between (1) SSVs that belong to the same acoustic class, (2) SSVs that belong to different acoustic classes but transmit the same food-quality information, or (3) SSVs that belong to different acoustic classes and transmit different types of food-quality information
VPFC neurons were modulated preferentially by transitions between SSVs that transmitted meaningfully different types of information about food quality. vPFC neurons were not modulated preferentially by transitions between SSVs that were acoustically distinct nor were they modulated preferentially by artificial stimuli with different bandwidths. These properties suggest that the vPFC may be involved in those higher-order computations that underlie the spontaneous categorization of natural categories and not simple perceptual feature extraction
Summary
Categorization is a natural and adaptive process seen in all animals. nature presents significant variation, animals typically ignore some sources of variation, while attending to others in the service of guiding adaptive responses. Most physiologically linked categorization studies involve extensive training and often, the use of artificial categories (e.g., dogs vs cats, Freedman, Riesenhuber, Poggio, & Miller, 2001; number discrimination of dots, Nieder, Freedman, & Miller, 2002). These studies, fundamental in terms of their articulation of key aspects of the categorization process, raise interesting questions about the extent to which the same neurophysiological circuits are engaged when animals spontaneously classify exemplars from more natural and biologically meaningful categories. Some forms of classification are relatively detached from the raw perceptual inputs and potentially entail more abstract concepts (Nieder et al, 2002; Sawamura, Shima, & Tanji, 2002)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
