Measurement of neuronal activity in a macaque monkey in response to animate images using near-infrared spectroscopy (NIRS)

Wakita Wakita

doi:10.3389/fnbeh.2010.00031

Abstract

Near-infrared spectroscopy (NIRS) has been used extensively for functional neuroimaging over the past decade, in part because it is considered a powerful tool for investigating brain function in human infants and young children, for whom other neuroimaging techniques are not suitable. In particular, several studies have measured hemodynamic responses in the occipital region in infants upon exposure to visual stimuli. In the present study, we used a multi-channel NIRS to measure neuronal activity in a macaque monkey who was trained to watch videos showing various circus animals performing acrobatic activities without fixing the head position of the monkey. Cortical activity from the occipital region was measured first by placing a probe comprising a 3 × 5 array of emitters and detectors (2 × 4 cm) on the area (area 17), and the robustness and stability of the results were confirmed across sessions. Cortical responses were then measured from the dorsofrontal region. The oxygenated hemoglobin signals increased in area 9 and decreased in area 8b in response to viewing the videos. The results suggest that these regions are involved in cognitive processing of visually presented stimuli. The monkey showed positive responsiveness to the stimuli from the affective standpoint, but its attentional response to them was an inhibitory one.

Highlights

The visual system of primates is remarkably efficient for analyzing information about objects present in complex natural scenes
The present experiment was undertaken in order to investigate whether both or either of these possibilities could be confirmed by measuring the neuronal activity of a macaque monkey while it was being exposed to videos of animals performing acrobatic activities
Discussion a left-sided shift was caused by the head movement of a macaque monkey as noted above, the near-infrared spectroscopy (NIRS) recordings of the cortical activity in the occipital region in response to visual stimulation in the monkey with minimal constraint were robust and stable

Summary

Introduction

The visual system of primates is remarkably efficient for analyzing information about objects present in complex natural scenes. Investigations with macaque monkeys have demonstrated that these animals can efficiently categorize targets such as animals (see Grand et al, 2008 for review). In some of those studies, for instance, monkeys responded rapidly by touching a screen when a target object was present in an image. According to previous literature about humans (Masataka, 2003), one could broadly hypothesize two possibilities regarding such salient features, that is, attention-getting properties and affective salience. The present experiment was undertaken in order to investigate whether both or either of these possibilities could be confirmed by measuring the neuronal activity of a macaque monkey while it was being exposed to videos of animals performing acrobatic activities.

Methods

Results

Conclusion