Chronic stress modulates the use of spatial and stimulus-response learning strategies in mice and man

Acute stress modulates multiple memory systems in favor of caudate nucleus-dependent stimulus-response and at the expense of hippocampus-dependent spatial learning and memory. We examined in mice and humans whether chronic stress has similar consequences. Male C57BL/6J mice that had been repeatedly exposed to rats ("rat stress") used in a circular hole board task significantly more often a stimulus-response strategy (33%) than control mice (0%). While velocity was increased, differences in latency to exit hole, distance moved or number of holes visited were not observed. Increased velocity and performance during retention trials one day later indicates altered emotionality and motivation to explore in rat stressed mice. Forty healthy young men and women were split into "high chronic stress" and "low chronic stress" groups based on their answers in a chronic stress questionnaire ("Trier Inventory of Chronic Stress"-TICS) and trained in a 2D task. A test trial immediately after training revealed that participants of the "high chronic stress" group used the S-R strategy significantly more often (94%) than participants of the "low chronic stress" group (52%). Verbal self-reports confirmed the strategy derived from participants' choice in the test trial. Learning performance was unaffected by the chronic stress level. We conclude that one consequence of chronic stress is the shift to more rigid stimulus-response learning, that is accompanied by changes in motivational factors in mice.     

Who is causing what? The sense of agency is relational and efferent-triggered

The sense of agency ("I did that") is a basic feature of our subjective experience. Experimental studies usually focus on either its attributional aspects (the "I" of "I did that") or on its motoric aspects (the "did" aspect of "I did that"). Here, we combine both aspects and focus on the subjective experience of the time between action and effect. Previous studies [Haggard, P., Aschersleben, G., Gehrke, J., & Prinz, W. (2002a). Action, binding and awareness. In W. Prinz, & B. Hommel (Eds.), Common mechanisms in perception and action: Attention and performance (Vol. XIX, pp. 266-285). Oxford: Oxford University Press] have shown a temporal attraction in the perceived times of actions and effects, but did directly not study the relation between them. In three experiments, time estimates of an interval between an action and its subsequent sensory effect were obtained. The actions were either voluntary key press actions performed by the participant or kinematically identical movements applied passively to the finger. The effects were either auditory or visual events or a passive movement induced to another finger. The results first indicated a shortening of the interval between one's own voluntary action and a subsequent effect, relative to passive movement conditions. Second, intervals initiated by observed movements, either of another person or of an inanimate object, were always perceived like those involving passive movements of one's own body, and never like those involving active movements. Third, this binding effect was comparable for auditory, somatic and visual effects of action. Our results provide the first direct evidence that agency involves a generalisable relation between actions and their consequences, and is triggered by efferent motor commands.     

Dynamic binding of identity and location information: a serial model of multiple identity tracking

Tracking of multiple moving objects is commonly assumed to be carried out by a fixed-capacity parallel mechanism. The present study proposes a serial model (MOMIT) to explain performance accuracy in the maintenance of multiple moving objects with distinct identities. A serial refresh mechanism is postulated, which makes recourse to continuous attention switching, a capacity-limited episodic buffer for identity-location bindings, indexed location information stored in the visuospatial short-term memory, and an active role of long-term memory. As identity-location bindings are refreshed serially, a location error is inherent for all other targets except the focally attended one. The magnitude of this location error is a key factor in predicting tracking accuracy. MOMIT’s predictions were supported by the data of five experiments: performance accuracy decreased as a function of target set-size, speed, and familiarity. A mathematical version of MOMIT fitted nicely to the observed data with plausible parameter estimates for the binding capacity and refresh time.     

Extending the Rorschach trauma content index and aggression indexes to dream narratives of children exposed to enduring violence: an exploratory study

In this study, we compared dream narratives of children and adolescents living under conditions of enduring interpersonal violence (n = 220) versus those living in peaceful surroundings (n = 99) on content variables that have been associated with traumatic experiences in Rorschach (Exner, 1995) imagery. As predicted, children and adolescents living in circumstances of enduring violence reported a higher proportion of content scorable by Armstrong and Loewenstein's (1990) Trauma Content Index and a much higher proportion of aggressive objects in their dreams (AgC; Gacono & Meloy, 1994). In support of discriminant validity, no consistent group differences were observed for the relative frequencies of Animal (A), Clothing (Cg), or Cooperative movement (COP) content. The modest association between manifest dream content and psychological symptom scales suggests that the former may alternatively reflect adaptive or psychopathological processes. Our findings suggest that content analysis of dreams may be a valuable adjunct in tapping the psychological state of children traumatized by violence.     

Temperament and migration patterns in Finland

Migration is a central determinant of population dynamics and structure. We examined whether three major temperament traits--sociability, emotionality, and activity--predicted migration propensity, selective urban-rural migration, and migration distance in a 9-year prospective study in Finland. The participants were Finnish women and men (N= 1,733) ages 15 to 30 years at baseline. The home municipality's position on the urban-rural continuum was assessed on the basis of the municipality's population density. We found that high sociability predicted migration to urban areas and longer migration distances. High activity increased general migration propensity (including migration to both urban and rural areas). High emotionality increased the likelihood of leaving the home municipality and decreased migration distances, but was not associated with selective urban-rural migration. These data suggest that temperament predicts the self-selection of environments on a demographic scale and may be relevant in understanding population dynamics.     

The Prospective and Retrospective Memory Questionnaire (PRMQ): factorial structure, relations to global subjective memory ratings, and Swedish norms

The factorial structure of the Prospective and Retrospective Memory Questionnaire (PRMQ; Smith et al., 2000) was examined in a Swedish population based sample (N= 540, age range; 35-90 years). Concurrent validity was assessed by relating PRMQ to global ratings of memory. Confirmatory factor analyses of the PRMQ items indicated a superior fit of a three-factor model, with prospective and retrospective memory as orthogonal factors and episodic memory as a common factor. Furthermore, the PRMQ scales correlated with the global ratings of memory, suggesting that each rating contributed with unique variance in predicting PRMQ scores. Given differences in levels of complaints as compared with prior research (Crawford et al., 2003) norms for the Swedish version are provided. In conclusion, the present findings extend earlier work by providing additional support for the construct and concurrent validity of the PRMQ scales.     

Does war beget child aggression? Military violence,gender, age and aggressive behavior in two Palestinian samples

We examined, first, the relations between children's exposure to military violence and their aggressive behavior and the role of age and gender in that relation in two Palestinian samples. Second, we tested parenting practices as a moderator of the relation between exposure to military violence and aggressive behavior, and third, whether exposure to military violence of different nature (direct victimization versus witnessing) has specific associations with different forms of aggression (reactive, proactive and aggression-enjoyment). Study I was conducted in a relatively calm military-political atmosphere in Palestine-Gaza, and included 640 children, aged 6-16 years whose parents (N=622) and teachers (N=457) provided reports. Older children (> or =12 years) provided self-reports (N=211). Study II included 225 Palestinian children aged 10-14-year, who participated during a high-violence period of the Al Aqsa Intifada characterized by air raids, killing and destruction. Results showed that witnessing severe military violence was associated with children's aggressive and antisocial behavior (parent-reported) in study I, and with proactive, reactive and aggression-enjoyment (child-reported) in the study II. As hypothesized, good and supporting parenting practices could moderate the link between exposure to military violence and aggressive behavior. Aggr.     

The cost of question concealment: eye-tracking and MEG evidence

Although natural language appears to be largely compositional, the meanings of certain expressions cannot be straightforwardly recovered from the meanings of their parts. This study examined the online processing of one such class of expressions: concealed questions, in which the meaning of a complex noun phrase (the proof of the theorem) shifts to a covert question (what the proof of the theorem is) when mandated by a sub-class of question-selecting verbs (e.g., guess). Previous behavioral and magnetoencephalographic (MEG) studies have reported a cost associated with converting an entity denotation to an event. Our study tested whether both types of meaning-shift affect the same computational resources by examining the effects elicited by concealed questions in eye-tracking and MEG. Experiment 1 found evidence from eye-movements that verbs requiring the concealed question interpretation require more processing time than verbs that do not support a shift in meaning. Experiment 2 localized the cost of the concealed question interpretation in the left posterior temporal region, an area distinct from that affected by complement coercion. Experiment 3 presented the critical verbs in isolation and found no posterior temporal effect, confirming that the effect of Experiment 2 reflected sentential, and not lexical-level, processing.     

Semantic processing of previews within compound words

Previous studies have suggested that previews of words prior to fixation can be processed orthographically, but not semantically, during reading of sentences (K. Rayner, D. A. Balota, & A. Pollatsek, 1986). The present study tested whether semantic processing of previews can occur within words. The preview of the second constituent of 2-constituent Finnish compound nouns was manipulated. The previews were either identical to the 2nd constituent or they were incorrect in the form of a semantically related word, a semantically unrelated word, or a semantically meaningless nonword. The results indicate that previews of 2nd constituents within compound words can be semantically processed. The results have important implications for understanding the nature of preview and compound word processing. These issues are crucial to developing comprehensive models of eye-movement control and word recognition during reading.     

NONEMPIRICAL REALITY: TRANSCENDING THE PHYSICAL AND SPIRITUAL IN THE ORDER OF THE ONE

I describe characteristic phenomena of quantum physics that suggest that reality appears to us in two domains: the open and well‐known domain of empirical, material things—the realm of actuality—and a hidden and invisible domain of nonempirical, non‐material forms—the realm of potentiality. The nonempirical forms are part of physical reality because they contain the empirical possibilities of the universe and can manifest themselves in the empirical world. Two classes of nonempirical states are discussed: the superposition states of microphysical entities, which are nonempirical because observation destroys them, and the virtual states of material systems, which are nonempirical because they are empty. The non‐empirical part to physical reality represents a predetermined and hidden order that exists before it is empirical, and the visible world is an emanation out of it. I discuss consequences for our understanding of human nature, the origin of life, and human values. Reality is an indivisible wholeness that is aware of its processes, like a Cosmic Spirit, and it reveals its awareness in the mindlike properties of elementary processes as well as in the human consciousness. Thus, one is led to G. W. F. Hegel's thesis that the Cosmic Spirit is thinking in us.