Motion Adaptation in Area MT

Abstract

In many sensory systems, exposure to a prolonged stimulus causes adaptation, which tends to reduce neural responses to subsequent stimuli. Such effects are usually stimulus-specific, making adaptation a powerful probe into information processing. We used dynamic random dot kinematograms to test the magnitude and selectivity of adaptation effects in the middle temporal area (MT) and to compare them to effects on human motion discrimination. After 3 s of adaptation to a random dot pattern moving in the preferred direction, MT neuronal responses to subsequent test patterns were reduced by 26% on average compared with adaptation to a static pattern. This reduction in response magnitude was largely independent of what test stimulus was presented. However, adaptation in the opposite direction changed responses less often and very inconsistently. Therefore motion adaptation systematically and profoundly affects the neurons in MT representing the adapted direction, but much less those representing the opposite direction. In human psychophysical experiments, such adapting stimuli affected direction discrimination, biasing choices away from the adaptation direction. The magnitude of this perceptual shift was consistent with the magnitude of the changes seen in area MT, if one assumes that a motion comparison step occurs after MT.

The Influence of Sustained Selective Attention on Stimulus Selectivity in Macaque Visual Area MT

“…Second, recent work on adaptation in area MT suggests that in our case, adaptation should rather strengthen direction selectivity instead of weaken it. This follows from the observation that neuronal responses are enhanced when a preferred motion stimulus is preceded by adapting motion in the opposite direction (van Wezel and Britten, 2002;Kohn and Movshon, 2003). Observations for the reverse constellation, nonpreferred preceded by preferred motion, show either reduced activity after long adaptation periods of 20 sec or more (Petersen et al, 1985;Kohn and Movshon, 2003) or unchanged activity after short adaptation periods of 3 sec (van Wezel and Britten, 2002).…”

Representation of auditory motion directions and sound source locations in the human planum temporale

“…17, 2018; relies on prolonged exposure to a particular motion direction, followed by the viewing of a stationary object, elicits the illusion of motion in the opposite direction, demonstrating an adaptation of specialized direction detecting mechanisms (Barlow and Hill, 1963). The effect of adaptation to a specific motion direction has been commonly observed in hMT+/V5 (He et al, 1998;Hogendoorn and Verstraten, 2013;Huk et al, 2001;Tootell et al, 1995;Van Wezel 2002). Similarly, behavioral studies have provided compelling evidence for motion selective (Deas et al, 2008;Guerreiro et al, 2016;Kitagawa and Ichihara, 2002;Reinhardt-Rutland and Anstis, 1982) and direction-sensitive auditory motion aftereffects (aMAEs) (Dong et al, 2000;Grantham, 1998;Grantham and Wightman, 1979;Neelon and Jenison, 2003).…”

The motion aftereffect reloaded

“…Important recent studies by Kohn and Movshon [24,25] measured adaptation-induced changes in the response of direction-selective cells in macaque MT (previously reported in [26,27]). One of their aims was to determine whether adaptation effects occur at the level of MT, or are inherited in responses fed forward from V1 cells.…”

“…The essential principle of population coding in the MAE is still universally accepted, but discoveries made possible with the introduction of new experimental techniques indicate that major changes to theoretical explanations of the MAE are required. These discoveries include work in human psychophysics [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], primate physiology [24][25][26][27], human neuroimaging [28][29][30][31][32][33][34][35][36][37], human electrophysiology (Visual Evoked Potentials -VEPs) [38][39][40][41][42] and transcranial stimulation [43][44][45]. Results indicate that the MAE is an amalgam of neural adaptation at several visual cortical sites.…”