Stimulus timing by people with Parkinson's disease

Previous literature suggests that Parkinson’s disease is marked by deficits in timed behaviour. However, the majority of studies of central timing mechanisms in patients with Parkinson’s disease have used timing tasks with a motor component. Since the motor abnormalities are a defining feature of the condition, the status of timing in Parkinson’s disease remains uncertain. Data are reported from patients with mild to moderate Parkinson’s disease (both on and off medication) and age- and IQ-matched controls on a range of stimulus timing tasks without counting. Tasks used were temporal generalization, bisection, threshold determination, verbal estimation, and a memory for duration task. Performance of patients was generally “normal” on all tasks, but significant differences from performance of controls were found on the memory for duration task. Among the “normal” effects noted were arithmetic mean bisection, asymmetric temporal generalization gradients, and subjective shortening on the memory for duration task. The results suggest (a) that some previous reports of timing “deficits” in Parkinson’s patients were possibly due to the use of tasks requiring a timed manual response and (b) small differences between patients and controls may be found on tasks where two stimuli are presented on each trial, whether patients are on medication or off it.     

The persistence of erroneous familiarity in an epileptic male: challenging perceptual theories of déjà vu activation

We report the case of a 39-year-old, temporal lobe epileptic male, MH. Prior to complex partial seizure, experienced up to three times a day, MH often experiences an aura experienced as a persistent sensation of déjà vu. Data-driven theories of déjà vu formation suggest that partial familiarity for the perceived stimulus is responsible for the sensation. Consequently, diverting attention away from this stimulus should cause the sensation to dissipate. MH, whose sensations of déjà vu persist long enough for him to shift his perceptual focus a number of times during the experience, spontaneously reports that these shifts make no difference to the sensation experienced. This novel observation challenges data-driven theories of déjà vu formation which have been used to explain the occurrence of déjà vu in those with temporal lobe epilepsy and the general population. Clearly, in epilepsy, erratic neuronal firing is the likely contributor, and in this paper we postulate that such brain firing causes higher-order erroneous 'cognitive feelings'. We tentatively extend this account to the general population. Rather than being a reaction to familiar elements in perceptual stimuli, déjà vu is likely to be the result of a cognitive feeling borne of the erroneous activation of neural familiarity circuits such as the parahippocampal gyrus, persisting as long as this activation persists.     

Influencing attitudes toward near and distant objects

It is argued that the temporal distance of attitude objects systematically changes how the object is mentally represented, and thus influences the strength of particular persuasive appeals. Three experiments tested the hypothesis that people preferentially attend to arguments that highlight primary, abstract (high-level) vs. incidental, concrete (low-level) features when attitude objects are temporally distant vs. near. Results suggested that when attitude objects are temporally distant vs. near, arguments emphasizing primary vs. secondary features (Study 1), desirability vs. feasibility features (Study 2), and general classes vs. specific cases are more persuasive (Study 3). The relation of construal theory to dual process theories of persuasion and persuasion phenomena, such as personal relevance effects and functional matching effects, are discussed.     

A survival guide to fission

The fission of a person involves what common sense describes as a single person surviving as two distinct people. Thus, say most metaphysicians, this paradox shows us that common sense is inconsistent with the transitivity of identity. Lewis’s theory of overlapping persons, buttressed with tensed identity, gives us one way to reconcile the common sense claims. Lewis’s account, however, implausibly says that reference to a person about to undergo fission is ambiguous. A better way to reconcile the claims of common sense, one that avoids this ambiguity, is to recognize branching persons, persons who have multiple pasts or futures.

解析现代生育伦理问题的思维路向

人类生育选择有以“善”为核心和以“正当”为核心的两类价值定位 ,因而 ,对现代生育伦理问题的理论解释 ,不能只是其中的任何一种思维路向 ,而应当是两种思维路向的合理整合。     

Manipulating cues in mind wandering: Verbal cues affect the frequency and the temporal focus of mind wandering

Our understanding of mind wandering (MW) has dramatically increased over the past decade. A key challenge still facing research is the identification of the processes and events that directly cause and control its occurrence. In the present study we sought to shed light on this question, by investigating the effects of verbal cues on the frequency and temporal focus of MW. To this aim, we experimentally manipulated the presence of irrelevant verbal cues during a vigilance task, in two independent groups (Verbal-cues group vs. No-cues group).We found that compared to the No-cues group, the Verbal-cues group reported a higher amount of MW, mostly triggered by the irrelevant cue-words, and a higher proportion of past-oriented MW compared to the other temporal orientations. These results demonstrate that task-irrelevant verbal stimulation increases the frequency of MW and steers its temporal orientation toward the past. Implications for the research on MW are discussed.     

Intertrial pellets influence the acquisition and expression of timed appetitive responding in rats

Two experiments examined temporally based changes in the conditioned magazine-entries of rats when a target food pellet arrived at a fixed time before the termination of a conditioned stimulus. Both experiments found that increasing the rate of intertrial pellets systematically interfered with the rate of acquisition. When intertrial pellets were featured in acquisition, their omission on test trials also resulted in a very poorly expressed conditioned response. On test trials preceded by intertrial pellets, however, peak times in groups trained with intertrial pellets were shifted in a rightward direction under a long but not short interstimulus interval. This rightward shift was accompanied by a smaller standard deviation. Our key findings are best accommodated by real-time associative models.     

Sharing with others and delaying for the future in preschoolers

This study explored age differences in preschoolers’ temporal and social discounting and the association of these abilities. Research indicates that 4-year-olds are sensitive to rewards of differing magnitude (Lemmon & Moore, 2007). However, it is unclear whether preschoolers are able to consider length of time when making a choice to delay (Mischel, Masters, & Grusec, 1969). In this study, 66, 3- and 4-year-olds were presented a delay of gratification task in which length of delay was manipulated. Additionally, they were given a sharing task in which they distributed toys between themselves, a friend, and another peer. Results suggested sensitivity to delay differences only in the oldest group. Furthermore, delay sensitivity was associated with sharing more preferred toys with friends compared to another peer, suggesting that favoring the “self” closer in time overlaps with favoring “another” who is closer socially.     

Perception of intersensory synchrony in audiovisual speech: not that special

Perception of intersensory temporal order is particularly difficult for (continuous) audiovisual speech, as perceivers may find it difficult to notice substantial timing differences between speech sounds and lip movements. Here we tested whether this occurs because audiovisual speech is strongly paired (“unity assumption”). Participants made temporal order judgments (TOJ) and simultaneity judgments (SJ) about sine-wave speech (SWS) replicas of pseudowords and the corresponding video of the face. Listeners in speech and non-speech mode were equally sensitive judging audiovisual temporal order. Yet, using the McGurk effect, we could demonstrate that the sound was more likely integrated with lipread speech if heard as speech than non-speech. Judging temporal order in audiovisual speech is thus unaffected by whether the auditory and visual streams are paired. Conceivably, previously found differences between speech and non-speech stimuli are not due to the putative “special” nature of speech, but rather reflect low-level stimulus differences.     

The ecological rationality of delay tolerance: insights from capuchin monkeys

Both human and non-human animals often face decisions between options available at different times, and the capacity of delaying gratification has usually been considered one of the features distinguishing humans from other animals. However, this characteristic can widely vary across individuals, species, and types of task and it is still unclear whether it is accounted for by phylogenetic relatedness, feeding ecology, social structure, or metabolic rate. To disentangle these hypotheses, we evaluated temporal preferences in capuchin monkeys, South-American primates that, despite splitting off from human lineage approximately 35 million years ago, show striking behavioural analogies with the great apes. Then, we compared capuchins’ performance with that of the other primate species tested so far with the same procedure. Overall, capuchins showed a delay tolerance significantly higher than closely related species, such as marmosets and tamarins, and comparable to that shown by great apes. Capuchins’ tool use abilities might explain their comparatively high preference for delayed options in inter-temporal choices. Moreover, as in humans, capuchin females showed a greater delay tolerance than males, possibly because of their less opportunistic foraging style. Thus, our results shed light on the evolutionary origins of self-control supporting explanations of delay tolerance in terms of feeding ecology.