The attentional blink (AB) represents a cognitive deficit in reporting the second of two targets (T2), when that second target appears 200-600msec after the first (T1). However, it is unclear how this paradigm impacts the subjective visibility (that is, the conscious perception) of T2, and whether the temporal profile of T2 report accuracy matches the temporal profile of subjective visibility. In order to compare report accuracy and subjective visibility, we asked participants to identify T1 and T2, and to rate the subjective visibility of T2 across two experiments. Event-related potentials were also measured. The results revealed different profiles for the report of T2 versus the subjective visibility of T2, particularly when T1 and T2 appeared within 200msec of one another. Specifically, T2 report accuracy was high but T2 visibility was low when the two targets appeared in close temporal succession, suggesting what we call the Experiential Blink is different from the classic AB. Electrophysiologically, at lag-1, the P3 component was modulated more by subjective visibility than by report accuracy. Collectively, the data indicate that the deficit in accurately reporting T2 is not the same as the deficit in subjectively experiencing T2. This suggests that traditional understandings of the AB may require adjustment and that, consistent with other findings, working memory encoding and conscious perception may not be synonymous.

Learned flavor preferences can be strikingly persistent in the face of behavioral extinction. Harris, Shand, Carroll, and Westbrook (2004) suggested that this persistence may be due to flavor preference conditioning's producing a long-lasting change in the hedonic response to the conditioned stimulus (CS ) flavor. In the present study, the CS flavor was presented in simultaneous compound with 16% sucrose, whereas the CS flavor was presented with 2% sucrose. During subsequent two-and one-bottle tests, the CS and CS flavors were presented in 2% sucrose. Hedonic reactions during training and test were assessed using an analysis of the microstructure of licking behavior. Conditioning resulted in greater consumption of the CS than of the CS that did not extinguish over repeated two-and one-bottle tests. The mean lick cluster size was higher for the CS than for the CS only on the first cycle of tests. Since lick cluster size can be used as an index of stimulus palatability, the present results indicate that although the hedonic reaction to the CSs did change, this was not maintained across repeated tests. Thus, changes in the hedonic response to the conditioned flavors cannot explain the resistance to the extinction of learned flavor preferences.

When conditioning involves a consistent temporal relationship between the conditioned stimulus (CS) and unconditioned stimulus (US), the expression of conditioned responses within a trial peaks at the usual time of the US relative to the CS. Here we examine the temporal profile of responses during conditioning with variable CS-US intervals. We conditioned stimuli with either uniformly distributed or exponentially distributed random CS-US intervals. In the former case, the frequency of each CS-US interval within a specified range is uniform but the momentary probability of the US (the hazard function) increases as time elapses during the trial; with the latter distribution, short CS-US intervals are more frequent than longer intervals, but the momentary probability of the US is constant across time within the trial. We report that, in a magazine approach paradigm, rats' response rates remained stable as time elapses during the CS when the CS-US intervals were uniformly distributed, whereas their response rates declined when the CS-US intervals were exponentially distributed. In other words, the profile of responding during the CS matched the frequency distribution of the US times, not the momentary probability of the US during the CS. These results are inconsistent with real-time associative models, which predict that associative strength tracks the momentary probability of the US, but may provide support for timing models of conditioning in which conditioned responding is tied to remembered times of reinforcement.

Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders.