From Freedom From to Freedom To: New Perspectives on Intentional Action

There are few concepts as relevant as that of intentional action in shaping our sense of self and the interaction with the environment. At the same time, few concepts are so elusive. Indeed, both conceptual and neuroscientific accounts of intentional agency have proven to be problematic. On the one hand, most conceptual views struggle in defining how agents can adequately exert control over their actions. On the other hand, neuroscience settles for definitions by exclusion whereby key features of human intentional actions, including goal-directness, remain underspecified. This paper reviews the existing literature and sketches how this gap might be filled. In particular, we defend a gradualist notion of intentional behavior, which revolves around the following key features: autonomy, flexibility in the integration of causal vectors, and control

The homuncular jigsaw: investigations of phantom limb and body awareness following brachial plexus block or avulsion

Many neuropsychological theories agree that the brain maintains a relatively persistent representation of one's own body, as indicated by vivid "phantom" experiences. It remains unclear how the loss of sensory and motor information contributes to the presence of this representation. Here, we focus on new empirical and theoretical evidence of phantom sensations following damage to or an anesthetic block of the brachial plexus. We suggest a crucial role of this structure in understanding the interaction between peripheral and central mechanisms in health and in pathology. Studies of brachial plexus function have shed new light on how neuroplasticity enables "somatotopic interferences", including pain and body awareness. Understanding the relations among clinical disorders, their neural substrate, and behavioral outcomes may enhance methods of sensory rehabilitation for phantom limbs

What are intentions?

The concept of intention can do useful work in psychological theory. Many authors have insisted on a qualitative difference between prospective and intentions regarding their type of content, with prospective intentions generally being more abstract than immediate intentions. However, we suggest that the main basis of this distinction is temporal: prospective intentions necessarily occur before immediate intention and before action itself, and often long before them. In contrast, immediate intentions occur in the specific context of the action itself. Yet both types of intention share a common purpose,namely that of generating the specific information required to transform an abstract representation of a goal-state into a concrete episode of instrumental action directed towards that goal. To this extent, the content of a prospective and of an immediate intention can actually be quite similar. The main distinction between prospective and immediate intentions becomes one of when, i.e., how early on, the episodic details of an action are planned. We propose that the conscious experience associated with intentional action comes from this process of fleshing out intentions with episodic details

Choosing to stop: responses evoked by externally triggered and internally generated inhibition identify a neural mechanism of will

Inhibiting inappropriate action is key to human behavioural control. Studies of action inhibition largely investigated external stop signals, yet these are rare in everyday life. Instead healthy adults exert "self-control," implying an ability to decide internally to stop actions. We added "choose for yourself" stimuli to a conventional go/no-go task to compare reactive versus intentional action and inhibition. No-go reactions showed the N2 EEG potential characteristic of inhibiting prepotent motor responses, whereas go reactions did not. Interestingly, the N2 component was present for intentional choices both to act and also to inhibit. Thus, free choices involved a first step of intentionally inhibiting prepotent responses before generating or withholding an action. Intentional inhibition has a crucial role breaking the flow of stimulus-driven responding, allowing expression of volitional decisions. Even decisions to initiate self-generated actions require this prior negative form of volition, ensuring the "freedom from immediacy" characteristic of human behaviour

Subliminal priming of intentional inhibition

AbstractIntentional choice is an important process underlying human behaviour. Intentional inhibition refers to the capacity to endogenously cancel an about-to-be-executed action at the last moment. Previous research suggested that such intentional inhibitory control requires conscious effort and awareness.Here we show that intentional decisions to inhibit are nevertheless influenced by unconscious processing. In a novel version of the Go/No-Go task, participants made speeded keypress actions to a Go target, or withheld responses to a No-Go target, or made free, spontaneous choices whether to execute or inhibit a keypress when presented with a free-choice target. Prior to each target, subliminal masked prime arrows were presented. Primes could be congruent with the Go or No-Go arrows, or neutral. Response times and proportion of action choices were measured. Primes were presented at latencies that would give either positive or negative compatibility effects (PCE, Experiment 1, and NCE, Experiment 2, respectively), based on previous literature.Go-primes at positive-compatibility latencies facilitated speeded response times as expected, but did not influence number of choices to act on free-choice trials. However, when Go primes were presented at negative-compatibility latencies, “free” decisions to inhibit were significantly increased. Decisions to act or not can be unconsciously manipulated, at least by inhibitory mechanisms. The cognitive mechanisms for intentionally withholding an action can be influenced by unconscious processing. We discuss possible moral and legal implications of these findings

Mapping the invisible hand: a body model of a phantom limb

After amputation, individuals often have vivid experiences of their absent limb (i.e., a phantom limb). Therefore, one’s conscious image of one’s body cannot depend on peripheral input only (Ramachandran & Hirstein, 1998). However, the origin of phantom sensations is hotly debated. Reports of vivid phantoms in the case of congenital absence of the limb show that memory of former body state is not necessary (Brugger et al., 2000). According to one view, phantoms may reflect innate organization of sensorimotor cortices (Melzack, 1990). Alternatively, phantoms could reflect generalization from viewing other people’s bodies (Brugger et al., 2000), a sensorimotor example of the classic theory that understanding oneself follows from understanding the “generalized other” (Mead, 1934, p. 154). Because phantom limbs cannot be stimulated, sensory testing cannot directly compare visual and somatosensory influences on representations of phantom limbs. Consequently, empirical investigation of phantoms is limited

Perception: A Motion After-Effect for Voluntary Actions

SummaryAfter viewing directional motion for a period of time, we experience a motion after-effect in which a subsequent stationary object appears to move in the opposite direction. A recent study demonstrates a novel motion after-effect that depends on the movement of the hand

A Dance to the Music of Time: Aesthetically-Relevant Changes in Body Posture in Performing Art

In performing arts, body postures are both means for expressing an artist's intentions, and also artistic objects, appealing to the audience. The postures of classical ballet obey the body's biomechanical limits, but also follow strict rules established by tradition. This combination offers a perfect milieu for assessing scientifically how the execution of this particular artistic activity has changed over time, and evaluating what factors may induce such changes. We quantified angles between body segments in archive material showing dancers from a leading company over a 60-year period. The data showed that body positions supposedly fixed by codified choreography were in fact implemented by very different elevation angles, according to the year of ballet production. Progressive changes lead to increasingly vertical positions of the dancer's body over the period studied. Experimental data showed that these change reflected aesthetic choices of naïve modern observers. Even when reduced to stick figures and unrecognisable shapes, the more vertical postures drawn from later productions were systematically preferred to less vertical postures from earlier productions. This gradual change within a conservative art form provides scientific evidence that aesthetic change may arise from continuous interaction between artistic tradition, individual artists' creativity, and a wider environmental context. This context may include social aesthetic pressure from audiences