Traveling waves in the prefrontal cortex during working memory

Abstract

Neural oscillations are evident across cortex but their spatial structure is not well- explored. Are oscillations stationary or do they form traveling waves, i.e., spatially organized patterns whose peaks and troughs move sequentially across cortex? Here, we show that oscillations in the prefrontal cortex (PFC) organized as traveling waves in the theta (4-8Hz), alpha (8-12Hz), and beta (12-30Hz) bands. Some traveling waves were planar while many rotated around an anatomical point. The waves were modulated during performance of a working memory task. During baseline conditions, waves flowed bidirectionally along a specific axis of orientation. During task performance, there was an increase in waves in one direction over the other, especially in the beta band. We discuss functional implications.

Propofol Anesthesia Alters Cortical Traveling Waves

“…Traveling waves could be detected by observing the gradient in oscillation phase values across the recording array (Bhattacharya et al 2021). Fig.…”

“…They can, for example, retain recent history of network activations, keep track of time, and may even perform computation (Muller et al 2018;Muller and Destexhe 2012;Heitmann and Ermentrout 2020;Ermentrout and Kleinfeld 2001). Experimental observations show that they change with task demands and impact behavior (Alamia and VanRullen 2019;Bhattacharya et al 2021). For example, when traveling waves in visual cortex are better organized, animals are better at detecting targets (Davis et al 2020).…”

“…Traveling waves in both awake and anesthetized animals show specific properties. They can be planar or rotational (Muller et al 2016;Bhattacharya et al 2021). They tend to flow in certain directions and have different degrees of organization and scale (Muller et al 2018).…”

“…To investigate this, we examined data from our previous study on the effects of propofol on cortical oscillatory power and coherence (Bastos et al 2021). We used methods previously employed to identify and document traveling waves in the prefrontal cortex during working memory (Bhattacharya et al 2021). Recordings were made from electrode arrays in three cortical areas: the ventrolateral prefrontal cortex, frontal eye fields and the auditory parabelt cortex of macaque monkeys.…”

Propofol anesthesia alters cortical traveling waves

“…They can, for example, retain recent history of network activations, keep track of time, and may even perform computation (Muller et al 2018;Muller and Destexhe 2012;Heitmann and Ermentrout 2020;Ermentrout and Kleinfeld 2001). Experimental observations show that they change with task demands and impact behavior (Alamia and VanRullen 2019;Bhattacharya et al 2021). For example, when traveling waves in visual cortex are better organized, animals are better at detecting targets (Davis et al 2020).…”