Previous studies have shown that saccadic eye responses but not manual responses were sensitive to the kind of warning signal used, with visual onsets producing longer saccadic latencies compared to visual offsets. The aim of the present study was to determine the effects of distinct warning signals on manual latencies and to test the premise that the onset interference, in fact, does not occur for manual responses. A second objective was to determine if the magnitude of the warning effects could be modulated by contextual procedures. Three experimental conditions based on the kind of warning signal used (visual onset, visual offset and auditory warning) were run in two different contexts (blocked and non-blocked). Eighteen participants were asked to respond to the imperative stimulus that would occur some milliseconds (0, 250, 500 or 750 ms) after the warning signal. The experiment consisted in three experimental sessions of 240 trials, where all the variables were counterbalanced. The data showed that visual onsets produced longer manual latencies than visual offsets in the nonblocked context (275 vs 261 ms; P < 0.001). This interference was obtained, however, only for short intervals between the warning and the stimulus, and was abolished when the blocked context was used (256 vs 255 ms; P = 0.789). These results are discussed in terms of bottom-up and top-down interactions, mainly those related to the role of attentional processing in canceling out competitive interactions and suppressive influences of a distractor on the relevant stimulus. Key wordsThere has been general agreement that reaction times are reduced when a warning signal (WS) precedes the onset of a subsequent stimulus -the imperative stimulus (IS) -to which a response must be given. Nevertheless, some studies have shown that the facilitation induced by the WS can be modulated by the kind of WS employed; for example, visual onset, visual offset or auditory warning. In two classical papers, Ross and Ross (1,2) showed that visual onset and visual offset used as WS produced different effects on saccade latency: saccadic reaction times obtained after visual offset were shorter

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O presente artigo tem o objetivo de mostrar a possibilidade da relação entre os campos da psicologia e da epigenética e como considerações secundárias, a possível relação entre psicopatologias - especialmente, a esquizofrenia - e epigenética. Com esse intuito, foram utilizados como base artigos científicos e livros que permeiam os temas da psicologia, psicopatologias, epigenética e esquizofrenia. A partir disso, foi delineado o percurso de formação da psicologia e do campo da epigenética, incluindo a forma como o último pode impactar o primeiro e gerar novas formas de compreensão sobre a prática do psicólogo. Com base nesta revisão, pode-se afirmar que a epigenética possui grande relevância para a psicologia e é capaz de proporcionar uma nova perspectiva para o campo de psicopatologias, seja sobre suas causas ou na constituição de direções de tratamento.

When the offset of a visual stimulus (GAP condition) precedes the onset of a target, saccadic reaction times are reduced in relation to the condition with no offset (overlap condition) -the GAP effect. However, the existence of the GAP effect for manual responses is still controversial. In two experiments using both simple (Experiment 1, N = 18) and choice key-press procedures (Experiment 2, N = 12), we looked for the GAP effect in manual responses and investigated possible contextual influences on it. Participants were asked to respond to the imperative stimulus that would occur under different experimental contexts, created by varying the array of warning-stimulus intervals (0, 300 and 1000 ms) and conditions (GAP and overlap): i) intervals and conditions were randomized throughout the experiment; ii) conditions were run in different blocks and intervals were randomized; iii) intervals were run in different blocks and conditions were randomized. Our data showed that no GAP effect was obtained for any manipulation. The predictability of stimulus occurrence produced the strongest influence on response latencies. In Experiment 1, simple manual responses were shorter when the intervals were blocked (247 ms, P < 0.001) in relation to the other two contexts (274 and 279 ms). Despite the use of choice key-press procedures, Experiment 2 produced a similar pattern of results. A discussion addressing the critical conditions to obtain the GAP effect for distinct motor responses is presented. In short, our data stress the relevance of the temporal allocation of attention for behavioral performance.

Manual reaction times (MRTs) are reduced when a warning signal precedes the onset of an imperative stimulus. The decrease in MRTs is modulated by uncertainty about the moment of stimulus occurrence after the warning stimulus. This modulation is related to preparatory mechanisms that occur during the foreperiod between the warning and imperative stimuli. Hence, manipulations within the range of foreperiods influence preparation and thus response latencies. When the moment of the occurrence of the imperative stimulus is highly predictable, volunteers can allocate resources in time to optimize their performance, a mechanism known as the temporal allocation of attention. In the present study, we evaluated the effects of temporal context (i.e., the duration and arrangement of intervals) on MRTs by conducting 2 experiments with different purposes. The first experiment verified which intervals were more susceptible to variations in the temporal context. The second experiment examined whether learning (i.e., practice) that is acquired by volunteers while in a temporal context affects performance if the temporal contexts are changed. Our data showed that short intervals were more susceptible to contextual influences. Participants could implicitly perceive the temporal context of the experiment and used this to optimize performance. Implicit learning obtained during a temporal context influenced response latencies for a period of time, even when the temporal context was changed. Our results complement many aspects of the results reported by other studies and confirm the importance of temporal attention for organizing and optimizing perception and behavioral performance.