Caudate nucleus-dependent response strategies in a virtual navigation task are associated with lower basal cortisol and impaired episodic memory

The present research examined the relationship between endogenous glucocorticoids, navigational strategies in a virtual navigation task, and performance on standard neuropsychological assessments of memory. Healthy young adult participants (N = 66, mean age: 21.7) were tested on the 4 on 8 virtual maze (4/8 VM) and standard neuropsychological tests such as the Rey-Osterrieth Complex Figure (RO) and the Rey Auditory Verbal Learning Task (RAVLT), which measure episodic memory. The 4/8 VM differentiates between navigational strategies, where participants either use a hippocampal-dependent spatial strategy by building relationships between landmarks, or a caudate nucleus-dependent stimulus–response strategy by automatizing a pattern of open and closed arms to learn the location of objects within the maze. Degree of stress was assessed by administering the Perceived Stress Scale (PSS) questionnaire. Cortisol samples were taken on two consecutive days upon waking, 30 min after waking, at 11 am, 4 pm, and 9 pm. There was a significant difference in basal levels of cortisol between spatial and response learners. Interestingly, response learners had significantly lower cortisol levels throughout the day. The two groups did not differ in terms of perceived stress as measured with the PSS questionnaire. Moreover, there was no significant correlation between PSS scores and salivary cortisol levels, indicating that the higher cortisol levels in the spatial group were not associated with greater perceived stress. In addition, participants who spontaneously used a spatial strategy performed significantly better on the RAVLT and RO. These data indicate that the cortisol levels in the spatial group may be optimal in terms of episodic memory performance whereas the cortisol levels in the response group may be associated with poorer memory. These results are suggestive of an inverted U-shaped curve describing the effects of basal levels of circulating cortisol on memory in young adults.     

An Intensive Outpatient Program for Veterans With Posttraumatic Stress Disorder and Traumatic Brain Injury

Post-9/11 service members may return from military service with a complicated set of symptoms and conditions, such as posttraumatic stress disorder (PTSD), depression, substance misuse, and traumatic brain injury (TBI), that interfere with reintegration and impair functioning. Although evidence-based treatments that facilitate recovery exist, their successful delivery at a sufficient dose is limited. Barriers to accessing treatment combined with challenges compiling a comprehensive treatment team further delay delivery of effective evidence-based care for PTSD, TBI, and co-occurring mental health conditions. This paper describes the development of a comprehensive, multidisciplinary, 2-week intensive day program for post-9/11 veterans with complex mental health concerns. The treatment program combines skill building groups, family education, and integrative health approaches with evidence-based individual PTSD or TBI care. Initial results from the first 132 participants were notable for a 97% completion rate, as well as statistically significant and clinically meaningful reductions in PTSD, neurobehavioral, and depression symptom severity for the 107 veterans who completed the PTSD track and the 21 who completed the TBI track. These data suggest the intensive program approach is an effective, well-tolerated model of treatment for post-9/11 veterans with PTSD and/or TBI. Future controlled studies should examine the effectiveness of this intensive model compared to standard evidence-based therapy delivery, as well as longitudinal outcomes.     

Stress and context in auditory word recognition

Recent work in psycholinguistics has revealed that the role of lexical stress in auditory word recognition may be a complex one involving other potential sources of information. In the present investigation, the nature of lexical stress effects on auditory word recognition in context is examined. The ability of subjects to identify words based on the prosodic pattern of the word is examined for the words in isolation and in a sentence context. The results revealed a small influence of stress on the identification of the stimulus waveforms relative to a large effect of context. The data indicate that lexical stress is used in the identification of the words; however, its role is minor compared to the importance of contextual information.This article is based on sections of a doctoral dissertation presented to Indiana University, Bloomington, Indiana. This research was supported in part by NIH research grant NS-12179-08 to Indiana University and a Graduate Student Grant-in-Aid of Research from Indiana University.     

On the role of bias in dissociated phonological priming effects: A reply to Goldinger (1999)

Phonological priming studies have revealed two dissociated effects: low-similarity facilitation and highsimilarity interference (Hamburger & Slowiaczek, 1996; Slowiaczek & Hamburger, 1992). Because these two effects are influenced by different variables, they most likely reflect different processes that occur during auditory word recognition. Goldinger (1999) suggests that one bias is responsible for all phonological priming effects. In this reply, we argue against such a position. Although low similarity facilitation is likely the product of this bias, the data on phonological priming indicate that the dissociated highsimilarity interference cannot be produced by the same mechanism. Instead, the data indicate that high-similarity interference may reflect lexical processes.     

Lexical and Metrical Stress in Word Recognition: Lexical or Pre-lexical Influences?

The influence of lexical stress and/or metrical stress on spoken word recognition was examined. Two experiments were designed to determine whether response times in lexical decision or shadowing tasks are influenced when primes and targets share lexical stress patterns (JUVenile–BIBlical [Syllables printed in capital letters indicate those syllables receiving primary lexical stress.]). The results did not support an effect of lexical stress on the organization of lexical memory. In Experiment 3 primes and targets whose first syllables shared lexical stress only (MUDdy–PASta), metrical stress only (alTHOUGH–PASta), both cues (LECtern–PASta), or neither cue (conTROL–PASta) revealed no priming effect. However, targets whose first syllables were strong were responded to faster than targets whose first syllables were weak. Experiment 4 manipulated the metrical stress patterns of bi-syllabic primes and targets. Targets with strong–weak metrical stress patterns were responded to more quickly than those with strong–strong or weak–strong patterns. Although the priming paradigm did not reveal an influence of lexical and metrical stress on the organization of lexical memory, the data do support an influence of strong syllables on the processing of auditorily presented words.     

Evidence for the automatic processing of prelexical codes in an orthographic but not a phonological task

The automatic activation of phonological and orthographic information in auditory and visual word processing was examined using a task-set procedure. Participants engaged in a phonological task (i.e., determining whether the letter “a” in a word sounded like /e/ or /æ/) or an orthographic task (i.e., determining whether the sound /s/ in a word was spelled with an “s” or a “c”). Participants were cued regarding which task to perform simultaneously with, or 750 ms before, a clear or degraded target. The stimulus clarity effect (i.e., clear words responded to faster than degraded words) was absorbed into the time that it took participants to identify the task on the basis of the cue in a simultaneous cue–target as compared to a delayed cue–target condition, but only for the orthographic task. These data are consistent with the claim that prelexical processing occurs in a capacity-free manner upon stimulus presentation when participants are trying to extract orthographic codes from words presented in the visual and auditory modalities. Such affirmative data were not obtained when participants attempted to extract phonological codes from words, since here the effects of stimulus clarity and cue delay were additive.     

What Determines Visual Statistical Learning Performance? Insights From Information Theory

In order to extract the regularities underlying a continuous sensory input, the individual elements constituting the stream have to be encoded and their transitional probabilities (TPs) should be learned. This suggests that variance in statistical learning (SL) performance reflects efficiency in encoding representations as well as efficiency in detecting their statistical properties. These processes have been taken to be independent and temporally modular, where first, elements in the stream are encoded into internal representations, and then the co‐occurrences between them are computed and registered. Here, we entertain a novel hypothesis that one unifying construct—the rate of information in the sensory input—explains learning performance. This theoretical approach merges processes related to encoding of events and those related to learning their regularities into a single computational principle. We present data from two large‐scale experiments with over 800 participants tested in support for this hypothesis, showing that rate of information in a visual stream clearly predicts SL performance, and that similar rate of information values leads to similar SL performance. We discuss the implications for SL theory and its relation to regularity learning.     

Is Lying Bound to Commitment? Empirically Investigating Deceptive Presuppositions,Implicatures, and Actions

Lying is an important moral phenomenon that most people are affected by on a daily basis—be it in personal relationships, in political debates, or in the form of fake news. Nevertheless, surprisingly little is known about what actually constitutes a lie. According to the traditional definition of lying, a person lies if they explicitly express something they believe to be false. Consequently, it is often assumed that people cannot lie by more indirectly communicating believed-false claims, for instance by merely conversationally implicating them. In this paper, we subject this claim to an empirical test. In a preregistered study of 300 participants, we investigate how people judge cases of implicit deceptions that would usually be excluded by the traditional definition of lying (i.e., conversational implicatures, presuppositions, and nonverbal actions). Our results show that people do in fact consider it possible to lie by indirect means, suggesting that people have a broader concept of lying than is usually assumed. Moreover, our findings indicate that lie judgments are closely tied to the extent to which agents are perceived as having committed themselves to the believed-false claims they have communicated. We discuss the implications of our results for the traditional definition of lying and propose a new commitment-based definition of lying that can account for the findings of our experiment.