Can Bayesianism Solve Frege’s Puzzle?

Philosophia - Chalmers (Mind, 125, 499–510, 2016), responding to Braun (Mind, 125, 469–497, 2016), continues arguments from Chalmers (Mind, 120, 587–636, 2011a) for the conclusion...     

A Semantics for Means-end Relations

There has been considerable work on practical reasoning in artificial intelligence and also in philosophy. Typically, such reasoning includes premises regarding means–end relations. A clear semantics for such relations is needed in order to evaluate proposed syllogisms. In this paper, we provide a formal semantics for means–end relations, in particular for necessary and sufficient means–end relations. Our semantics includes a non-monotonic conditional operator, so that related practical reasoning is naturally defeasible. This work is primarily an exercise in conceptual analysis, aimed at clarifying and eventually evaluating existing theories of practical reasoning (pending a similar analysis regarding desires, intentions and other relevant concepts). “They were in conversation without speaking. They didn’t need to speak. They just changed reality so that they had spoken.” Terry Pratchett, Reaper Man     

Feedback functions, optimization, and the relation of response rate to reinforcer rate

The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate was arranged according to a quadratic equation with a maximum at a unique response rate. The experiment consisted of two phases, during which 6 Long Evans rats lever pressed for food. In the first phase of the experiment, the rats responded on six fixed-interval-plus-quadratic-feedback schedules, and in the second phase the rats responded on three variable-interval-plus-quadratic-feedback schedules. Responding in both phases was inconsistent with a one-to-one relation of response rate to reinforcer rate. Instead, different response rates were obtained at equivalent reinforcer rates. Responding did vary directly with the vertex of the feedback function in both phases, a finding consistent with optimization of reinforcer rate. The present results suggest that the feedback function relating reinforcer rate to response rate imposed by a reinforcement schedule can be an important determinant of behavior. Furthermore, the present experiment illustrates the benefit of arranging feedback functions to investigate assumptions about the variables that control schedule performance.     

Do you remember where sounds,pictures and words came from? The role of the stimulus format in object location memory

Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.     

Exploring the process of progressive disorientation

While an increasing number of behavioral studies examining spatial cognition use experimental paradigms involving disorientation, the process by which one becomes disoriented is not well explored. The current study examined this process using a paradigm in which participants were blindfolded and underwent a succession of 70° or 200° passive, whole body rotations around a fixed vertical axis. After each rotation, participants used a pointer to indicate either their heading at the start of the most recent turn or their heading at the start of the current series of turns. Analyses showed that in both cases, mean pointing errors increased gradually over successive turns. In addition to the gradual loss of orientation indicated by this increase, analysis of the pointing errors also showed evidence of occasional, abrupt loss orientation. Results indicate multiple routes from an oriented to a disoriented state, and shed light on the process of becoming disoriented.     

Effects of adding a second reinforcement alternative: implications for Herrnstein's interpretation of r(e)

Herrnstein's hyperbola describes the relation between response rate and reinforcer rate on variable-interval (VI) schedules. According to Herrnstein's (1970) interpretation, the parameter r(e) represents the reinforcer rate extraneous to the alternative to which the equation is fitted (the target alternative). The hyperbola is based on an assumption that extraneous reinforcer rate remains constant with changes in reinforcer rate on the target alternative (the constant-r(e) assumption) and that matching with no bias and perfect sensitivity occurs between response and reinforcer ratios. In the present experiment, 12 rats pressed levers for food on a series of 10 VI schedules arranged on the target alternative. Across conditions, six VI values and extinction were arranged on a second alternative. Reinforcer rate on the second alternative, r2, negatively covaried with reinforcer rate on the target alternative for five of the six VI values on the second alternative, and significant degrees of bias and undermatching occurred in response ratios. Given covariation of reinforcer rate on the second and target alternatives, the constant-r(e) assumption can be maintained only by assuming that reinforcer rate from unmeasured background sources, rb, covaries with reinforcer rate on the second alternative such that their sum, r(e), remains constant. In a single-schedule arrangement, however, r(e) equals rb and thus rb is assumed to remain constant, forcing a conceptual inconsistency between single- and concurrent-schedule arrangements. Furthermore, although an alternative formulation of the hyperbola can account for variations in bias and sensitivity, the modified equation also is based on the constant-r(e) assumption and therefore suffers from the same logical problem as the hyperbola when reinforcer rate on the second alternative covaries with reinforcer rate on the target alternative.     

Divergence between community psychologists in academic and nonacademic settings: A closer look at the implications

The ecological principle of interdependence has been a guiding theme in our research and conceptualization. For the development of community psychology, academic and applied interest and networks must be integrated in ways which value the views and resources of both groups. This is the focus of Kelly's (1984) remarks. The dynamic interplay of ideas, data, and practices is likely to facilitate the collaboration between researchers and setting inhabitants which Trickett (1984) describes as the distinctive quality of community psychology. Common pathways of information exchange, joint responsibility for training future members of the field, and mutually enhancing role relationships are needed. Current channels of communication provide little ease of access or incentives for participation by psychologists in nonacademic settings. It thus becomes the reponsibility of all concerned community psychologists to use their organizational skills to redress this harmful imbalance (Kelly, 1984). For this to occur, however, we must take the initial steps of frankly recognizing differences in our folkways and organizational constraints, while also emphasizing our common values and assets. The largest threat to the field is external constraints from university and clinical service settings on the work that represents community psychology (Elias et al., 1984). If we are dividedor uninformed in the face of these environmental presses, we will never create the adaptive niche that community psychology needs to survive.     

Group Session Rating Scale: Preliminary psychometrics in substance abuse group interventions

Background: Although ultra‐brief outcome and process measures have been developed for individual therapy, currently there are no ultra‐brief alliance measures for group therapy. Method: The current study examined 105 clients in group therapy for issues related to substance abuse or with issues related to the substance abuse of a significant other. We tested whether a newly developed group therapy alliance measure – the Group Session Rating Scale would be related to other commonly used group process measures (Working Alliance Inventory, Group Cohesion, Group Climate) and early change (change over the first four sessions of group therapy). Results: The findings provided support for reliability based on Cronbach alphas and test‐retest coefficients. Additionally, the GSRS was a one‐factor measure that was related to other group process measures as well as predicted early change. Discussion: Clinical implications for how to utilise ultra‐brief outcome and alliance measures are provided.     

Music-to-language transfer effect: may melodic ability improve learning of tonal languages by native nontonal speakers?

In tonal languages, as Mandarin Chinese and Thai, word meaning is partially determined by lexical tones. Previous studies suggest that lexical tones are processed by native listeners as linguistic information and not as pure tonal information. This study aims at verifying if, in nontonal languages speakers, the discrimination of lexical Mandarin tones varies in function of the melodic ability. Forty-six students with no previous experience of Mandarin or any other tonal language were presented with two short lists of spoken monosyllabic Mandarin words and invited to perform a same–different task trying to identify whether the variation were phonological or tonal. Main results show that subjects perform significantly better in identifying phonological variations rather than tonal ones and interestingly, the group with a high melodic ability (assessed by Wing subtest 3) shows a better performance exclusively in detecting tonal variations.