Abstract
Visual short-term memory (VSTM) load was previously shown to impair perception of visual stimuli presented during the maintenance period. However, it is unclear if these effects depend exclusively on the sensory demands of the VSTM task or if they also depend on the attentional demands during VSTM maintenance. Specifically, if these effects depend solely on the sensory demands of VSTM, then taxing sensory capacity in high VSTM load is expected to impair perception of visual stimuli but not auditory stimuli. However, if these effects also depend on attentional capacity, then VSTM load will impair perception of both visual and auditory stimuli. We present behavioral data testing this prediction. Thirty participants performed a delayed-match-to-sample VSTM task of either low (one colored square) or high (four colored squares) VSTM load. Participants responded to an auditory stimulus detection task during the VSTM maintenance period. The auditory detection stimulus (1000 Hz pure tone) was presented randomly in half of the trials at a predetermined, individual threshold level. Strong evidence was found in favor of a negative correlation between auditory detection sensitivity (d’) and reaction time (BF > 10), unveiling speed-accuracy trade-off (SAT) in auditory perception. Conditioned accuracy function analyses indicated that beyond the SAT effects, high VSTM load (compared to low VSTM load) leads to reduced detection sensitivity (d’) of an auditory stimulus during VSTM maintenance (BF = 8.952). The results supplement evidence of impaired perception due to VSTM load beyond the visual modality, demonstrating the cross-modal effects of VSTM load on auditory perception. These findings support the account that the effects of VSTM load on perception depend on attentional demands during the high load VSTM maintenance period.