Conspecific images require longer visual processing than simple stimuli in healthy four-week old piglets.

Swine are a common neurobehavioral model. Visual event related potentials (VERPs) are an electroencephalogram (EEG) technique that assesses visual processing and can inform brain function and sensory changes after trauma or disease. We hypothesized that piglet visual EEG processing for 2D conspecific (CS) images would produce more cortical activity than a simple white square stimulus. We measured VERPs in healthy piglets presented with a 2D CS piglet image (5) and compared these results with animals presented with a simple white square (WS, 5). EEG waveforms were input into a source localization model of the brain to estimate cortical activity. N1 and P2 amplitudes and latencies and current density were extracted for each animal. Visual processing of CS produced longer N1 and P2 latencies than WS in the visual processing regions, suggesting that pigs may require longer processing times for more detailed images. Contrary to our hypothesis, CS had lower P2 amplitudes (frontal and left temporal) and current density (right temporal and occipital), which suggests that CS requires less processing power. Magnitudes may be related to the brightness of the stimuli presented (a feature that was not controlled for) with WS having on average a higher lux (112) than CS (98). Regardless, latency differences between CS and WS demonstrate that visual processing is sensitive to subtle stimulus features which can inform future studies on pig behavior and attention. Finally, these data serve as a healthy reference to compare VERPs in experimental cohorts subject to brain injury or other neurological diseases affecting visual processing.