Comparison of emotional responses in monkeys with rhinal cortex or amygdala lesions.

Abstract

Four emotionally arousing stimuli were used to probe the behavior of monkeys with bilateral ablations of the entorhinal and perirhinal cortex. The animals' behavioral changes were then contrasted with those observed earlier (Meunier et al., 1999)

Responses to Affective Stimuli in Monkeys with Entorhinal or Perirhinal Cortex Lesions

“…Rh lesions have also been detailed previously, the present animals corresponding to cases Rh 2-4 and 6 -7 in Meunier et al (1993Meunier et al ( , 1996, respectively. Case Rh-1 did not undergo affective testing, and atypical case Rh-5, which showed compulsive motor stereotypies rather than exaggerated defense, is discussed in detail in Meunier and Bachevalier (2002). In all five cases, damage was symmetrical and extensive, including, on average, 70% (range 42-82%) of ERh volume together with 86% (range 77-97%) of PRh volume, with the same sparing as separate lesions, and only minor unintended damage.…”

“…The subjects were eight individually housed, adult rhesus monkeys (Macaca mulatta), four (two male and two female) received aspiration lesions of the entorhinal cortex (ERh), and four (three male and one female) received aspiration lesions of the perirhinal cortex (PRh). Data from these two groups were compared with those of six (male) unoperated controls (N) and five (two male and three female) with combined entorhinal and perirhinal ablations (Rh) (Meunier and Bachevalier, 2002). All operated monkeys had been previously tested using DNMS with trial-unique object (Meunier et al, 1993).…”

“…The apparatus, stimuli, recording procedure, and scoring method were identical to those used previously (Meunier et al, 1999;Meunier and Bachevalier, 2002). Monkeys were in a Wisconsin General Testing Apparatus.…”

“…This ethogram is the same as that used previously (Meunier et al, 1999;Meunier and Bachevalier, 2002) except for the exclusion of activities that were either rare (viz., frown) or ambiguous (viz., piloerection, which can occur with both fear and aggression). Like earlier group Rh, groups ERh and PRh did not differ significantly from controls in their general behavior recorded before and after stimulus presentation.…”

“…In a previous study, the behavioral responses to affectively salient stimuli of monkeys with rhinal cortex ablations (Meunier and Bachevalier, 2002) were compared with those of monkeys with neurotoxic or aspiration amygdala lesions (Meunier et al, 1999). Four stimuli probed affective functions (construed in a broad sense encompassing social behavior, emotion, and motivation): two with a social component (an unfamiliar human and a conspecific stimulus) and two nonsocial items (a generally rewarded object and a toy snake).…”