Single unit analysis of auditory processing in squirrel monkey frontal cortex

Abstract

Clicks, tone bursts and species-specific vocalizations were used to test 315 units isolated in the dorsolateral prefrontal cortex. Acoustic responses were detected in about 20% of the units. Responsive units were scattered throughout the explored area, although more units responsive to vocalizations were found in the vicinity of sulcus principalis. Vocalizations were effective stimuli, driving 68% of the acoustic units. However, only 19% responded exclusively to vocalizations. Clicks were effective for 65% of the acoustic units, 27% of which responded only to clicks. Tones activated 39% of the acoustic units. Units generally responded to tones over a wide frequency range. Responses to tones, clicks and vocalization were similar, both within the same unit and between units. The biggest difference related to the background activity of the unit: Low rate cells produced a small number of relatively well-timed discharges per stimulus; high rate cells produced a longer, more poorly-timed response. Vocalizations differed in their effectiveness according to their physical structure. Noisy calls elicited 69% of all responses, although they accounted for only one-third of the test vocalizations. We conclude that frontal acoustic units are involved with at least two functional mechanisms, one related to attending to a large class of sounds, the other related to the detection of sounds with high motivational significance.

Selectivity for the Spatial and Nonspatial Attributes of Auditory Stimuli in the Ventrolateral Prefrontal Cortex

“…Anatomically, the vPFC is located anterior to the arcuate sulcus and area 8a and lies below the principal sulcus (Romanski and Goldman-Rakic, 2002), as shown in Figure 3. Physiologically, vPFC neurons were characterized by their strong responses to species-specific vocalizations and noise bursts (Newman and Lindsley, 1976;Romanski and GoldmanRakic, 2002).…”

The Neurophysiology of Functionally Meaningful Categories: Macaque Ventrolateral Prefrontal Cortex Plays a Critical Role in Spontaneous Categorization of Species-Specific Vocalizations

“…The vPFC is located anterior to the arcuate sulcus and area 8a and lies below the principal sulcus (Cohen, Russ, Gifford, Kiringoda, & MacLean, 2004;Romanski & Goldman-Rakic, 2002). vPFC neurons were further characterized by their strong responses to auditory stimuli (Cohen et al, 2004;Romanski & GoldmanRakic, 2002;Newman & Lindsley, 1976).…”

Domain specificity in the primate prefrontal cortex

“…Responses to acoustic stimuli have only been sporadically noted in the frontal lobes of Old and New World monkeys (Benevento, Fallon, Davis, & Rezak, 1977;Bodner, Kroger, & Fuster, 1996;Newman & Lindsley, 1976;Tanila, Carlson, Linnankoski, & Kahila, 1993;Tanila, Carlson, Linnankoski, Lindroos, & Kahila, 1992;Wollberg & Sela, 1980) without determining a specific locus for auditory prefrontal neurons. Examination of these studies indicates that few of the studies sampled neurons in ventrolateral and orbito-frontal regions with complex auditory stimuli.…”