Frames, Biases, and Rational Decision-Making in the Human Brain

Abstract

Human choices are remarkably susceptible to the manner in which options are presented. This socalled "framing effect" represents a striking violation of standard economic accounts of human rationality, although its underlying neurobiology is not understood. We found that the framing effect was specifically associated with amygdala activity, suggesting a key role for an emotional system in mediating decision biases. Moreover, across individuals, orbital and medial prefrontal cortex activity predicted a reduced susceptibility to the framing effect. This finding highlights the importance of incorporating emotional processes within models of human choice and suggests how the brain may modulate the effect of these biasing influences to approximate rationality.A central tenet of rational decision-making is logical consistency across decisions, regardless of the manner in which available choices are presented. This assumption, known as "extensionality" (1) or "invariance" (2), is a fundamental axiom of game theory (3). However, the proposition that human decisions are "description-invariant" is challenged by a wealth of empirical data (4, 5). Kahneman and Tversky originally described this deviation from rational decision-making, which they termed the "framing effect," as a key aspect of prospect theory (6, 7).Theories of decision-making have tended to emphasize the operation of analytic processes in guiding choice behavior. However, more intuitive or emotional responses can play a key role in human decision-making (8-10). Thus, when taking decisions under conditions when available information is incomplete or overly complex, subjects rely on a number of simplifying heuristics, or efficient rules of thumb, rather than extensive algorithmic processing (11). One suggestion is that the framing effect results from systematic biases in choice behavior arising from an affect heuristic underwritten by an emotional system (12, 13). However, despite the substantial role of the framing effect in influencing human decision-making, the underlying neurobiological basis is not understood.We investigated the neurobiological basis of the framing effect by means of functional magnetic resonance imaging (fMRI) and a novel financial decision-making task. Participants (20 university students or graduates) received a message indicating the amount of money that they would initially receive in that trial (e.g., "You receive £50"). Subjects then had to choose between a "sure" option and a "gamble" option presented in the context of two different frames. The "sure" option was formulated as either the amount of money retained from the initial starting amount (e.g., keep £20 of the £50; "Gain" frame) or as the amount of money lost from the initial amount (e.g., lose £30 of the £50; "Loss" frame). The "gamble" option was identical in both frames and was represented as a pie chart depicting the probability of winning or losing ( Fig. 1) (14).The behavioral results indicated that subjects' decisions were significantly affected by our framing...

Valence and salience contribute to nucleus accumbens activation

“…Economic behavior and brain activation both respond to incentive magnitude differently depending on whether the incentive is a gain or a loss relative to a reference point (De Martino et al, 2006;Friedman and Savage, 1948;Kahneman and Tversky, 1979;Tom et al, 2007). Tom et al (2007) recently found NAcc responses to mixed gambles decreased more steeply with loss magnitude than they increased with gain magnitude.…”

O modelo estrutural de Freud e o cérebro: uma proposta de integração entre a psicanálise e a neurofisiologia

“…Acredita-se que o córtex pré-frontal e o córtex orbitofrontal recebam aferências da amígdala, as quais representam o valor motivacional dos estímulos, integrando-os e promovendo uma avaliação do comportamento futuro que será adotado 25 .…”

“…O córtex cingulado anterior parece ser importante para a modulação das informações processadas pelo córtex pré-frontal 25 . Estudos de neuroimagem demonstram que processos executivos são mediados pelo córtex frontal, particularmente o córtex cingulado anterior e o córtex pré-frontal.…”

Neurobiologia das emoções

“…O CPFVM e o COF mantêm importante relação com a amígdala e ambos contribuem para a tomada de decisões, embora os mecanismos pelos quais isto ocorra sejam distintos. Acreditase que essas regiões corticais recebam aferências da 53 .…”

“…Embora a amígdala não estabeleça conexão direta com o córtex lateral pré-frontal, ela se comunica com o córtex cingulado anterior e o córtex orbital, os quais estão envolvidos nos circuitos da memória, tornando possível a justificativa de alguns autores de que a amígdala participa na modulação da memória e na integração de informações emocionais e cognitivas, possivelmente atribuindo-lhes carga emocional, possibilitando a transformação de experiências subjetivas em experiências emocionais 24,53 . Lesões no córtex pré-frontal medial rostral levam à expressão inapropriada das emoções nos comportamentos sociais e ao prejuízo na tomada de decisões pessoalmente vantajosas 28 .…”