The Indeterminacy of Translation: Fifty Years Later

The paper considers the Quinean heritage of the argument for the indeterminacy of translation. Beyond analyzing Quine’s notion of stimulus meaning, the paper discusses two Kripkean argument’s against the Quinean claim that dispositions can provide the basis for an account of meaning: the Normativity Argument and the Finiteness Argument. An analogy between Kripke’s arguments and Hume’s argument for epistemological skepticism about the external world will be drawn. The paper shows that the answer to Kripke’s rule-following skepticism is analogous to the answer to Humean skepticism: our use of concepts is more basic than, and presupposed by, the statement of the skeptical problem itself.

Naturalist Structuralism's Aporia? Essentialism, Indeterminacy, and Nostalgia – a response to Paul Livingston

This essay argues that what Livingston calls the “structuralist” project, combined with a naturalistic, external approach to language, does not in fact lead to a paradoxical failure to match lived language. Quine’s indeterminacy argument is not a consequence of naturalism and structuralism, but is rather a consequence of thorough anti-essentialism, a thesis he shares with Derrida and Davidson. Contemporary naturalism is in fact not committed to Quine’s thesis. Davidson’s views are a purification of the views of Quine, removing Quine’s empiricist appeal to stimulus meaning and Quine’s scientism. Davidson abandons the conventionalist conception of language but retains the “structuralist” conception of language, as captured by a truth-definition. The indeterminacy thesis is a consequence of anti-essentialism applied to semantics, that is, the denial of transcendental signifieds. The essay concludes by arguing that Quine’s aporia (which is also Davidson’s and Derrida’s aporia) is a discovery rather than a paradox.

Inhibition of thoughts and actions in obsessive-compulsive disorder: extending the endophenotype?

BackgroundObsessive-compulsive disorder (OCD) has been associated with impairments in stop-signal inhibition, a measure of motor response suppression. The study used a novel paradigm to examine both thought suppression and response inhibition in OCD, where the modulatory effects of stimuli relevant to OCD could also be assessed. Additionally, the study compared inhibitory impairments in OCD patients with and without co-morbid depression, as depression is the major co-morbidity of OCD.MethodVolitional response suppression and unintentional thought suppression to emotive and neutral stimuli were examined using a novel thought stop-signal task. The thought stop-signal task was administered to non-depressed OCD patients, depressed OCD patients and healthy controls (n=20 per group).ResultsMotor inhibition impairments were evident in OCD patients, while motor response performance did not differ between patients and controls. Switching to a new response but not motor inhibition was affected by stimulus relevance in OCD patients. Additionally, unintentional thought suppression as measured by repetition priming was intact. OCD patients with and without depression did not differ on any task performance measures, though there were significant differences in all self-reported measures.ConclusionsResults support motor inhibition deficits in OCD that remain stable regardless of stimulus meaning or co-morbid depression. Only switching to a new response was influenced by stimulus meaning. When response inhibition was successful in OCD patients, so was the unintentional suppression of the accompanying thought.

Role of an Identified Looming-Sensitive Neuron in Triggering a Flying Locust's Escape

Flying locusts perform a characteristic gliding dive in response to predator-sized stimuli looming from one side. These visual looming stimuli trigger trains of spikes in the descending contralateral movement detector (DCMD) neuron that increase in frequency as the stimulus gets nearer. Here we provide evidence that high-frequency (>150 Hz) DCMD spikes are involved in triggering the glide: the DCMD is the only excitatory input to a key gliding motor neuron during a loom; DCMD-mediated EPSPs only summate significantly in this motor neuron when they occur at >150 Hz; when a looming stimulus ceases approach prematurely, high-frequency DCMD spikes are removed from its response and the occurrence of gliding is reduced; and an axon important for glide triggering descends in the nerve cord contralateral to the eye detecting a looming stimulus, as the DCMD does. DCMD recordings from tethered flying locusts showed that glides follow high-frequency spikes in a DCMD, but analyses could not identify a feature of the DCMD response alone that was reliably associated with glides in all trials. This was because, for a glide to be triggered, the high-frequency spikes must be timed appropriately within the wingbeat cycle to coincide with wing elevation. We interpret this as flight-gating of the DCMD response resulting from rhythmic modulation of the flight motor neuron's membrane potential during flight. This means that the locust's escape behavior can vary in response to the same looming stimulus, meaning that a predator cannot exploit predictability in the locust's collision avoidance behavior.

Mechanisms of Discourse Comprehension Impairment After Right Hemisphere Brain Damage

This study examined the generality of a previous finding indicating that difficulty suppressing or inhibiting context-inappropriate interpretations is an important predictor of narrative discourse comprehension for adults with right brain damage RBD) (C. A. Tompkins, A. Baumgaertner, M. T. Lehman, & W. Fassbinder, 2000). Forty adults with RBD and 39 without brain damage listened to two-sentence stimuli and judged whether a probe word fit with the overall stimulus meaning. An ambiguous initial sentence elicited both dominant and less preferred inferences, and the second sentence resolved the ambiguity toward the initially less-likely interpretation. Probes represented the dominant inference for the first sentence and were presented at two poststimulus intervals. Probe judgment response times indicated that neither group suppressed the eventually inappropriate inferences in the time intervals studied. However, multiple regression analysis demonstrated that for individual participants with RBD, the extent of suppression from one interval to the next was a significant predictor of performance on a specialized measure of inference comprehension. The discussion evaluates these findings and identifies directions for future research.