Differing time dependencies of object recognition memory impairments produced by nicotinic and muscarinic cholinergic antagonism in perirhinal cortex

The roles of muscarinic and nicotinic cholinergic receptors in perirhinal cortex in object recognition memory were compared. Rats' discrimination of a novel object preference test (NOP) test was measured after either systemic or local infusion into the perirhinal cortex of the nicotinic receptor antagonist methyllycaconitine (MLA), which targets alpha-7 (α7) amongst other nicotinic receptors or the muscarinic receptor antagonists scopolamine, AFDX-384, and pirenzepine. Methyllycaconitine administered systemically or intraperirhinally before acquisition impaired recognition memory tested after a 24-h, but not a 20-min delay. In contrast, all three muscarinic antagonists produced a similar, unusual pattern of impairment with amnesia after a 20-min delay, but remembrance after a 24-h delay. Thus, the amnesic effects of nicotinic and muscarinic antagonism were doubly dissociated across the 20-min and 24-h delays. The same pattern of shorter-term but not longer-term memory impairment was found for scopolamine whether the object preference test was carried out in a square arena or a Y-maze and whether rats of the Dark Agouti or Lister-hooded strains were used. Coinfusion of MLA and either scopolamine or AFDX-384 produced an impairment profile matching that for MLA. Hence, the antagonists did not act additively when coadministered. These findings establish an important role in recognition memory for both nicotinic and muscarinic cholinergic receptors in perirhinal cortex, and provide a challenge to simple ideas about the role of cholinergic processes in recognition memory: The effects of muscarinic and nicotinic antagonism are neither independent nor additive.     

Clinical Considerations in the Treatment of Substance Use Disorders with Veterans

This article addresses issues associated with the treatment of substance use disorders (SUD) in the U.S. veteran population. First, we examine special considerations regarding the assessment of alcohol and drug use in veterans. Second, we discuss current treatment approaches that have demonstrated efficacy in this population, with special consideration the issue of co-morbidity (especially SUD and Posttraumatic Stress Disorder). Third, we discuss two strategies to coordinate treatment of SUD: stepped care as a way to implement these treatments for SUD alone, and integrated treatment for SUD and co-morbid disorders. Finally, we discuss promising future directions for the treatment of SUD in the veteran population, including examination of mechanisms of behavior change, formal involvement of the veteran’s family in treatment, and use of existing datasets.     

Risk for injury in preschoolers: relationship to attention deficit hyperactivity disorder.

Parental ratings of preschoolers' risk for injury, direct assessment of preschoolers' behavior thought related to risk for injury (e.g., Inattention, impulsivity) and number of documented injuries were examined in preschoolers with Attention Deficit Hyperactivity Disorder (ADHD) and their non-ADHD peers (Control). Of preschoolers with ADHD, 58.3% exhibited behavior which placed them at-risk for physical injury (0% Control), and their performance was significantly poorer on clinic-based tests. Nonetheless, preschoolers with ADHD did not actually sustain significantly more injuries which warranted medical treatment in an emergency department. Although preschoolers with ADHD may be at increased risk for minor injuries, further research is needed to determine whether they more frequently sustain more serious injuries.     

How many voices did you hear? Natural variability disrupts identity perception from unfamiliar voices

Our voices sound different depending on the context (laughing vs. talking to a child vs. giving a speech), making within‐person variability an inherent feature of human voices. When perceiving speaker identities, listeners therefore need to not only ‘tell people apart’ (perceiving exemplars from two different speakers as separate identities) but also ‘tell people together’ (perceiving different exemplars from the same speaker as a single identity). In the current study, we investigated how such natural within‐person variability affects voice identity perception. Using voices from a popular TV show, listeners, who were either familiar or unfamiliar with this show, sorted naturally varying voice clips from two speakers into clusters to represent perceived identities. Across three independent participant samples, unfamiliar listeners perceived more identities than familiar listeners and frequently mistook exemplars from the same speaker to be different identities. These findings point towards a selective failure in ‘telling people together’. Our study highlights within‐person variability as a key feature of voices that has striking effects on (unfamiliar) voice identity perception. Our findings not only open up a new line of enquiry in the field of voice perception but also call for a re‐evaluation of theoretical models to account for natural variability during identity perception.     

Flexible voices: Identity perception from variable vocal signals

Human voices are extremely variable: The same person can sound very different depending on whether they are speaking, laughing, shouting or whispering. In order to successfully recognise someone from their voice, a listener needs to be able to generalize across these different vocal signals (‘telling people together’). However, in most studies of voice-identity processing to date, the substantial within-person variability has been eliminated through the use of highly controlled stimuli, thus focussing on how we tell people apart. We argue that this obscures our understanding of voice-identity processing by controlling away an essential feature of vocal stimuli that may include diagnostic information. In this paper, we propose that we need to extend the focus of voice-identity research to account for both “telling people together” as well as “telling people apart.” That is, we must account for whether, and to what extent, listeners can overcome within-person variability to obtain a stable percept of person identity from vocal cues. To do this, our theoretical and methodological frameworks need to be adjusted to explicitly include the study of within-person variability.

     

Space aliens and nonwords: stimuli for investigating the learning of novel word-meaning pairs.

We describe a set of pictorial and auditory stimuli that we have developed for use in word learning tasks in which the participant learns pairings of novel auditory sound patterns (names) with pictorial depictions of novel objects (referents). The pictorial referents are drawings of "space aliens," consisting of images that are variants of 144 different aliens. The auditory names are possible nonwords of English; the stimulus set consists of over 2,500 nonword stimuli recorded in a single voice, with controlled onsets, varying from one to seven syllables in length. The pictorial and nonword stimuli can also serve as independent stimulus sets for purposes other than word learning. The full set of these stimuli may be downloaded from www.psychonomic.org/archive/.     

Person factors associated with suicidal behavior among African American women and men

This study compared person risk factors among the following groups of low-income, African American adults in an urban, public hospital: (a) suicide attempters and nonattempters, (b) male and female attempters, and (c) all 4 groups (50 female attempters, 50 female nonattempters, 50 male attempters, and 50 male nonattempters). Participants completed psychological distress, aggression, substance use, cognitive processes, religiosity/spirituality, and ethnic identity measures. Compared with nonattempters, attempters reported more psychological distress, aggression, substance use, and maladaptive coping strategies; less religiosity/spirituality; and lower levels of ethnic identity. Male attempters endorsed more substance use than female attempters. No person risk factors differentiated among the 4 groups. Assessment of person risk factors and implementation of commensurate culturally competent interventions are recommended.     

Better the Devil You Know? High-Risk Individuals’ Anticipated Psychological Responses to Genetic Testing for Melanoma Susceptibility

Purpose: The psychological consequences of genetic testing for mutations among individuals at increased risk of developing melanoma remain unexamined. The present study aimed to explore anticipated emotional, behavioral, cognitive, and familial responses to hypothetical genetic testing for melanoma susceptibility. Methods: Forty semi-structured interviews were undertaken with affected (n=20) and unaffected (n=20) individuals at either high or average risk of developing melanoma due to family history. Results: In-depth thematic analysis revealed that, in response to being identified as a mutation carrier, most participants with a family history anticipated calmly accepting their increased risk; either increasing precaution adoption or maintaining already vigilant behavioral practices; perceiving such information as important and valuable; and communicating genetic test results to family members, despite the acknowledgement of potential difficulties. In response to being identified as a non-carrier, the majority of participants expected to feel relieved; to maintain current precautionary health practices; to still perceive themselves at some risk of developing melanoma; and to be wary of the potential negative behavioral consequences of disclosing such information to family members. Women appeared more likely than men to acknowledge the potential for depression and worry following genetic testing. In contrast, more males than females expected to carry a gene mutation, and viewed their current preventive practices as optimum. Conclusion: Genetic testing for melanoma risk is likely to elicit a complex array of emotional, behavioral, cognitive, and familial responses for both testees and their family members, and these responses are likely to bear subtle differences for males and females.     

The effects of the presence of a face and direct eye gaze on voice identity learning

We rarely become familiar with the voice of another person in isolation but usually also have access to visual identity information, thus learning to recognize their voice and face in parallel. There are conflicting findings as to whether learning to recognize voices in audiovisual vs audio-only settings is advantageous or detrimental to learning. One prominent finding shows that the presence of a face overshadows the voice, hindering voice identity learning by capturing listeners' attention (Face Overshadowing Effect; FOE). In the current study, we tested the proposal that the effect of audiovisual training on voice identity learning is driven by attentional processes. Participants learned to recognize voices through either audio-only training (Audio-Only) or through three versions of audiovisual training, where a face was presented alongside the voices. During audiovisual training, the faces were either looking at the camera (Direct Gaze), were looking to the side (Averted Gaze) or had closed eyes (No Gaze). We found a graded effect of gaze on voice identity learning: Voice identity recognition was most accurate after audio-only training and least accurate after audiovisual training including direct gaze, constituting a FOE. While effect sizes were overall small, the magnitude of FOE was halved for the Averted and No Gaze conditions. With direct gaze being associated with increased attention capture compared to averted or no gaze, the current findings suggest that incidental attention capture at least partially underpins the FOE. We discuss these findings in light of visual dominance effects and the relative informativeness of faces vs voices for identity perception.     

Speech timing in Parkinson''s and Huntington''s disease

The purpose was to determine the effects of two different basal ganglia diseases on speech planning, initiation, and production. Patients with Parkinson's Disease (PD) and Huntington's Disease (HD) were compared with normal subjects on speech timing tasks. Speech reaction time was unimpaired, while changes in duration at different speech rates were affected differently in the two patient groups. In HD, changes in the duration of syllables, of pauses between phrases, and of sentences were all reduced, while in PD only the control of sentence duration was impaired. The HD patients had reduced syllable repetition rates, but both patient groups maintained their repetition rates over 5 sec. The ratios of word to phrase time, and of phrase to sentence time, remained constant across regular and fast speaking rates and did not differ from normal in either patient group. The results suggest that PD and HD patients are not impaired in speech planning or initiation, but have poor control over the duration of speech events.