The impact of selective amygdala, orbital frontal cortex, or hippocampal formation lesions on established social relationships in rhesus monkeys (Macaca mulatta)

Christopher J. Machado, Jocelyne Bachevalier

Research output: Contribution to journalArticle

126 Scopus citations

Abstract

Social dominance, personality ratings, and frequency, duration, and timing of social behaviors were measured pre- and postsurgically in 6 groups of rhesus monkeys (Macaca mulatta), each consisting of 1 sham-operated control and 1 monkey each with a selective amygdala, hippocampal, or orbital frontal cortex lesion. Unlike previous reports, none of the operated groups showed changes in social dominance postsurgery, although changes in other measures varied by lesion site. Although sham-operated monkeys displayed heightened avoidant, anxious, and aggressive behaviors, those with hippocampal lesions also showed increased exploration and excitability, along with reduced responses to affiliative signals. Amygdala lesions yielded several personality changes that precluded positive social interactions (increased exploration and excitability, decreased affiliation and popularity) and altered responses to threatening social signals. By contrast, monkeys with orbital frontal lesions were involved in more aggressive interactions and responded differently to both affiliative and threatening signals. Although several findings differ from earlier nonhuman primate studies, they are largely in agreement with human data and emphasize the context-specific nature of social behavior studies. Interpretation of results in relation to cognitive processes mediated by each structure is discussed.

Original languageEnglish (US)
Pages (from-to)761-786
Number of pages26
JournalBehavioral Neuroscience
Volume120
Issue number4
DOIs
StatePublished - Aug 2006

Keywords

  • Amygdala
  • Hippocampal formation
  • Macaque
  • Orbital frontal cortex
  • Social behavior

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Clinical Psychology

Fingerprint Dive into the research topics of 'The impact of selective amygdala, orbital frontal cortex, or hippocampal formation lesions on established social relationships in rhesus monkeys (Macaca mulatta)'. Together they form a unique fingerprint.

Cite this