On quoting the empty expression

Roy Sorensen has argued that a certain technical use of quotation marks to name the empty string supports a revised version of Davidson’s theory of quotation. I point out that Sorensen’s considerations provide no support for Davidson’s original theory, and I show that at best they support the revised Davidsonian theory only to the same extent that they support a simpler revised version of a Tarskian theory.     

Hierarchical Bayes Models for Response Time Data

Human response time (RT) data are widely used in experimental psychology to evaluate theories of mental processing. Typically, the data constitute the times taken by a subject to react to a succession of stimuli under varying experimental conditions. Because of the sequential nature of the experiments there are trends (due to learning, fatigue, fluctuations in attentional state, etc.) and serial dependencies in the data. The data also exhibit extreme observations that can be attributed to lapses, intrusions from outside the experiment, and errors occurring during the experiment. Any adequate analysis should account for these features and quantify them accurately. Recognizing that Bayesian hierarchical models are an excellent modeling tool, we focus on the elaboration of a realistic likelihood for the data and on a careful assessment of the quality of fit that it provides. We judge quality of fit in terms of the predictive performance of the model. We demonstrate how simple Bayesian hierarchical models can be built for several RT sequences, differentiating between subject-specific and condition-specific effects.     

Relation Between EMG Activation Patterns and Kinematic Properties of Aimed Arm Movements

Aimed flexion movements of the arm of different amplitude and duration were studied. Velocity and acceleration traces of movements with equal duration but different amplitude were equal, apart from a scaling factor (ratio between movement amplitudes). After appropriate scaling, EMG activity of the first agonist burst for these movements superimposed. This was not true for EMG activity in the antagonist muscle.

For movements with equal amplitude, but different duration, the time to peak acceleration was constant for all MT’s. Except for this fact, traces of acceleration, velocity, and agonist activity following the time of peak acceleration were about equal after appropriate scaling in time and amplitude. The integral of EMG activity in the first agonist burst increased linearly with peak velocity. For the antagonist burst, the integrated EMG activity increased more than proportionally.

During movements made as fast as possible, subjects used a different strategy by varying the duration of the accelerating phase for movements of different amplitude. Movement amplitude was achieved by adjusting the duration of the agonist burst and the onset time for the antagonist muscle. Amplitude of the antagonist burst was constant within a narrow range for movements of different amplitude.

These results did not change when the inertial mass was doubled by loading the arm with an additional mass.     

“We will work for you” – Social influence may suppress individual food preferences in a communicative situation in dogs

The level of motivation (i.e. incentive power) is thought to be one of the most important factors affecting performance and learning in various tasks. We investigated whether reward quality has an effect on the performance of family dogs in a two-way object choice test in which they can find the hidden food by relying on distal momentary human pointing cues. In three experiments we varied (1) the type of food reward according to the subjects’ own preference; (2) the quality of the reward offered at the same time in the indicated and not-indicated locations; and (3) the order of the high or low quality rewards in consecutive sessions. In Experiment 1, we first tested whether dogs prefer one kind of reward over another. Then one group was tested with the ‘preferred’ food as reward in the indicated bowl, while dogs in the other group received the ‘non-preferred’ food as reward. We did not find any difference between the performance and choice latencies of the two groups. In Experiment 2 for the first group, the indicated bowl contained a piece of carrot and the not-indicated bowl was empty. In the second group the indicated bowl contained carrot, but the not-indicated bowl contained sausage. According to a preliminary preference test, most dogs prefer sausage over carrot invariably. After 20 trials, the two groups performed surprisingly similarly. There was no difference found between groups in the number of correct choices, incorrect choices and non-choices. However, the comparison between the first and last five trials revealed that subjects who found sausage when they chose the not-indicated bowl (did not follow the pointing) chose the non-indicated bowl significantly more often toward the end of their test session. In Experiment 3, each dog received two sessions with 12 pointing trials in each. For the first session, one group was rewarded with sausage and the other with carrot upon choosing the indicated bowl. In the second session, the indicated bowl contained dry dog food for both groups. We found that correct choices and response latencies did not change over two sessions in the ‘sausage’ group. In the ‘carrot’ group, the dogs chose faster in the second session, but their performance did not improve; in fact, they chose the not-indicated bowl more often than the indicated bowl. As a conclusion, we can say that reward quality had some effect on dogs’ choice behavior in these experiments. The drop in their performance was not drastic, taking into account the general refusal to eat one of the ‘rewards’ (carrot) during the preference tests and also during the test trials. It seems that incentive contrast may play a relatively minor role in dog-human social interactions. Appropriate reward quality can be very important in asocial problem solving tasks, but, when interacting with humans, following human signals may override the effect of changed incentive power.     

The Dyadic Relationships Test: Creation and Validation of a Model-Derived,Visual-Verbal Instrument to Evaluate Couples Part I of II

Abstract

In Part I of this article, background and rationale for the construction of a Selfhood model-derived visual-verbal Dyadic Relationships Test (DRT) is presented. Results from studies covering its reliability and verification of its psychometric properties are presented. Construct validity was evaluated through research with competing theoretical models. In Part II, results from studies are reported through discriminant and concurrent validity analyses in adoptive and traditional couples. A revision evaluated its construct validity with measures of negotiation, intimacy, and communication, and through relational and emotional life at different stages of the life cycle, including empty nest and retirement. Results from these studies tend to support the psychometric properties of this instrument and, indirectly, the validity of the Selfhood model underlying its construction.     

The vicissitudes of affect in Horney's theory

Abstract

Karen Horney, a Neo-Freudian analyst who immigrated from Germany to the USA, undertook the difficult task of developing a theory that remained concrete psychology without resorting to biology or to metapsychological entelechies. Although her basic construct, as in Freud, is a conflict between nature and culture, nature for her is the naturally endowed real self, which the neurotic abandons bowing to cultural pressures. This process of desertion is teleological and based on imagination, and is also creative. It entails the pursuit of a god-like idealized image of the self shaped according to narrow and despoiled values. Being interpersonal, Horney's theory avoids third-person objectification which creates a false distance; it thus remains (inter)subjective. A theory of interpersonal affect, it is dramatic before being dynamic. It also abandons claims to universality as it does to the “objectivity” of the natural sciences. Horney's focus on alienation brings her close to Hegel and Marx, a neglected fact, and she pioneered feminist and self-help theories. The difficulty in reading Horney is not her abstruseness, since her theory refuses technicism. It resides rather in that resistance created by what Althusser called interpellation: one feels her finger pointed at oneself as one reads.