How the mind shapes action: Offline contexts modulate involuntary episodic retrieval

Involuntary retrieval of previous stimulus–response episodes is a centerpiece of many theories of priming, episodic binding, and action control. Typically it is assumed that by repeating a stimulus from trial n–1 to trial n, involuntary retrieval is triggered in a nearly automatic fashion, facilitating (or interfering with) the to-be-executed action. Here we argue that changes in the offline context weaken the involuntary retrieval of previous episodes (the offline context is defined to be the information presented before or after the focal stimulus). In four conditions differing in cue modality and target modality, retrieval was diminished if participants changed the target selection criterion (as indicated by a cue presented before the selection took place) while they still performed the same task. Thus, solely through changes in the offline context (cue or selection criterion), involuntary retrieval can be weakened in an effective way.     

Switching attention between modalities: further evidence for visual dominance

The present study examined cross-modal selective attention using a task-switching paradigm. In a series of experiments, we presented lateralized visual and auditory stimuli simultaneously and asked participants to make a spatial decision according to either the visual or the auditory stimulus. We observed consistent cross-modal interference in the form of a spatial congruence effect. This effect was asymmetrical, with higher costs when responding to auditory than to visual stimuli. Furthermore, we found stimulus-modality-shift costs, indicating a persisting attentional bias towards the attended stimulus modality. We discuss our findings with respect to visual dominance, directed-attention accounts, and the modality-appropriateness hypothesis.     

Activation of learned action sequences by auditory feedback

The present research addressed whether auditory feedback associated with a learned action sequence can activate the action representation of that sequence. Nonpianist participants learned to perform two melodies at a piano keyboard repeatedly during a trial. The participants heard feedback either from the melody they were performing (normal feedback) or from the other learned melody (termed alternate feedback). An additional tone functioned as an instruction cue to either switch melodies or continue the current melody. Following the instruction cues, participants typically paused just before switching, and paused similarly during trials with a continue cue. Participants paused longer after a continue cue when they experienced alternate rather than normal feedback. This effect was specific to instruction cues positioned at weak metrical accents—positions at which participants were less likely to switch overall. Feedback did not influence timing on switch trials. These findings indicate that influences of auditory feedback can activate learned action sequences, leading to longer latencies associated with cue evaluation.     

Response-repetition effects in task switching - dissociating effects of anatomical and spatial response discriminability

In task switching, response repetitions typically lead to performance benefits for task repetitions but costs for task switches. We examined whether this cost–benefit pattern is affected by response discriminability (RD), varying (a) the anatomical response separation (within-hand vs. between-hand responses) and (b) the spatial separation (close vs. far response keys). We assumed that anatomical RD increases response competition generally, whereas spatial RD increases the salience of left–right coding and thus facilitates response selection. In two experiments, we found that spatial RD increased the response-repetition costs in task switches but similarly decreased the response-repetition benefit in task repetitions. The effect of spatial RD was response-specific but did not interact with task switching. This data pattern is consistent with a recent account that proposed that facilitated response selection increases response “self-inhibition” after response execution. In contrast, the influence of anatomical RD primarily consisted of an overall increase of reaction-time level in all conditions, whereas error rates decreased, suggesting a general shift in response criterion. Taken together, the data suggest that a self-inhibition mechanism on the level of motor response codes contributes to response-repetition effects in task switching, which is possibly independent of task-specific mechanisms of strengthening of associations.     

Visual rivalry without spatial conflict

Visual rivalry has been extensively characterized in the literature. It is thought to require spatial conflict between overlapping visual presentations, even in studies that have found nonspatial (i.e., nonretinal) influences on rivalry. Unexpectedly, we identified visual rivalry in the complete absence of spatial conflict. Participants experienced visual rivalry when we placed a nonambiguous motion stimulus in a nonspatial (in our case, object-based) reference frame. Moreover, a stimulus that was displaced within a nonspatial reference frame did not induce rivalry despite the presence of spatial conflict. This finding shows that nonspatial, object-based processing can overrule retinotopic processing and prevent rivalry from occurring when a perceived stimulus exists unambiguously in an object-based reference frame. Our results identify a potent high-level conflict-resolution stage independent of low-level spatial visual conflict. This independence of spatial overlap provides an advantage to the visual system, allowing conflict resolution when an object is nonstationary on the retina (e.g., during frequently occurring eye movements).     

The VA Maryland Health Care System's telemental health program

The VA Maryland Health Care System introduced videoconferencing technology to provide psychiatry, evidenced-based psychotherapy, case management, and patient education at rural clinics where it was difficult to recruit providers. Telemental health services enable rural clinics to offer additional services, such as case management and patient education. Services have been expanded to urban outpatient clinics where a limited number of mental health clinic hours are available. This technology expands the availability of mental health providers and services, allowing patients to receive services from providers located at distant medical centers.     

Temporal structure coding with and without awareness

In order to interpret a constantly changing environment, visual events far apart in space and time must be integrated into a unified percept. While spatial properties of invisible signals are known to be encoded without awareness, the fate of temporal properties remains largely unknown. Here, we probed temporal integration for two distinct motion stimuli that were either visible or rendered invisible using continuous flash suppression. We found that when invisible, both the direction of apparent motion and the gender of point-light walkers were processed only when defined across short time periods (i.e., respectively 100 ms and 1000 ms). This limitation was not observed under full visibility. These similar findings at two different hierarchical levels of processing suggest that temporal integration windows shrink in the absence of perceptual awareness. We discuss this phenomenon as a key prediction of the global neuronal workspace and the information integration theories of consciousness.