Beyond the attentional blink: Visual masking by object substitution.

Abstract

If 2 targets are to be identified among distractors displayed in rapid sequence, correct identification of the 1st target hinders identification of the 2nd. To obtain this additional blink (AB), the 1st target must be masked with a simultaneous (integration) or a delayed (interruption) mask indifferently. In 3 experiments, it was shown that the 2nd target must also be masked, but that the precise form of masking is important: An AB occurs with interruption but not with integration masking. This nonequivalence of masking paradigms parallels that found in studies of masked priming, a phenomenon arguably related to the AB. The results are explained by a revised 2-stage model (M. M. Chun & M. C. Potter, 1995). Visual attention can be deployed over space or over time. Deployment over space has been studied extensively with several different paradigms (see reviews by Kinchla, 1992, and by LaBerge. 1990), Deployment over time has been studied less extensively, mainly with two related paradigms. In one paradigm, known as rapid serial visual presentation (RSVP), stimuli are presented sequentially in the same location, and observers are asked to identify one or more targets within the stream. When two targets are to be reported, the first is identified almost perfectly, but identification of the second is substantially impaired. The impairment is most evident when the second target is presented with a temporal lag of about 200-500 ms after the first (Raymond, Shapiro, & Arnell, 1992). At shorter or longer lags, performance is impaired less or not at all, thus yielding a characteristic U-shaped function over lags. This secondtarget deficit, also known as the attentiona! blink (AB), is said to occur because processing mechanisms required commonly by the two targets are unavailable (or are less available) for processing the second target until first-target processing has been completed (e.g., Chun & Potter, 1995). A very similar second-target deficit has been obtained in an elegantly simplified paradigm in which two targets, masked by trailing pattern-masks, are displayed at different screen locations, at various temporal lags from each other (Duncan, Ward, & Shapiro, 1994). The terms attentianal blink and

Topographic Contribution of Early Visual Cortex to Short-Term Memory Consolidation: A Transcranial Magnetic Stimulation Study

“…The similar findings of both experiments suggest that interference of activity in visual cortex reliably impaired memory consolidation, thereby affecting memory performance. Our findings are in line with previous interference studies that showed a critical window for VSTM consolidation up to 500 ms after stimulus offset (Chun and Potter, 1995;Magnussen et al, 1996;Giesbrecht and Di Lollo, 1998;Jolicoeur and Dell'Acqua, 1998;Lalonde and Chaudhuri, 2002;Vogel et al, 2006), and reveal a neurophysiological correlate of this consolidation window that includes activation states of topographic early visual cortex, which suggests that VSTM representations may be formed or maintained in sensory brain areas that encoded the stimuli. To our knowledge, we are the first to show that topographic early visual cortex is functionally relevant for short-term consolidation of sensory visual information.…”

“…Therefore, TMS may decrease the strength of or overwrite the neural representation of the memory trace in visual cortex. This suggestion is in line with propositions of object substitution in visual memory after presentation of a competing stimulus (Giesbrecht and Di Lollo, 1998;Enns and Di Lollo, 2000). Furthermore, our finding of a lateralized TMS effect on memory performance suggested that the neural memory representation was retinotopically organized, with limited transfer of memorized information to other parts of the visual field (Karni and Sagi, 1993;Schoups et al, 1995;Dill and Fahle, 1997).…”

“…The temporal window for visual short-term consolidation may last ϳ500 ms into the retention interval (Shapiro et al, 1994;Chun and Potter, 1995;Giesbrecht and Di Lollo, 1998;Jolicoeur and Dell'Acqua, 1998;Lalonde and Chaudhuri, 2002;Vogel et al, 2006). Earlier studies using the attentional blink paradigm showed that identification of a target stimulus is impaired if it is presented 200 -500 ms after an initial stimulus (Shapiro et al, 1994;Chun and Potter, 1995).…”

Blink and Shrink: The Effect of the Attentional Blink on Spatial Processing.

“…It has been proposed that the mask contributes to the attentional blink because it interferes with (e.g., replaces or prevents the consolidation of) the target information in visual working memory (Brehaut et al, 1999;Giesbrecht & Di Lollo, 1998). If this is the case, then this would be a likely explanation for the effects here, too.…”

Characterizing the Cortical Activity through Which Pain Emerges from Nociception

“…The experimental paradigm we used bears some resemblance to the attentional blink paradigm, in which two visual targets are presented within a continuous flow of nontarget stimuli (Raymond et al, 1992). Studies using such paradigms have shown that, when the time interval between the two target stimuli is short (typically Ͻ500 ms) and when the second target stimulus is quickly masked by a subsequent stimulus, the ability to detect the second target is significantly impaired (Giesbrecht and Di Lollo, 1998). This attentional blink phenomenon is thought to result from the early cortical representation of the second target being overwritten by the subsequent nontarget stimulus, while the central processes required for its consolidation are still engaged by the first target.…”