Pupil dilation during memory encoding reflects time pressure rather than depth of processing.

Under cognitive load theory, time pressure/urgency-induced arousal is a major contributor to pupil dilation during cognition. However, pupillometric encoding studies have failed to consider the possible role of time pressure/urgency effects, instead often assuming that encoding dilations directly reflect encoding strength. To isolate possible encoding strength and time pressure effects, we manipulated levels of processing (deep vs.