Name: face recognition and upside-down faces
Uploaded: 2023-04-30T06:46:13.000Z
Duration: 6 min 13 s
Channel: JoVE
Description: Face recognition is a specialized part of human perception. It often feels effortless, but it actually depends on complex and intensive processing. The brain uses dedicated networks to detect faces and tell them apart.

K12 Standards

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

Life Science

Structure and Function

HS-LS1-2.

The Inverted-face Effect

1. equipo y estímulos
<ol>
	<li>Este experimento requiere un ordenador y un experimento scripting software.</li>
	<li>Además, el experimento requiere de un conjunto relativamente grande de imágenes faciales, preferentemente con condiciones de iluminación similares y sin expresiones emocionales. Muchas bases de datos de este tipo de imágenes están disponibles libremente para fines de investigación. Un buen recurso es la base de datos de cara MIT: http://web.mit.edu/emeyers/www/face_databases.html#oulu</li>
</ol>
2. diseño
<ol>
	<li>Montar un conjunto de 80 imágenes faciales. Dividirlos por la mitad, en dos grupos de 40. Usar un grupo en la parte de la exposición incidental del experimento y reservar el otro grupo como hojas en la porción de prueba.<ol>
		<li>Tenga en cuenta que los dos grupos deben tener las mismas proporciones relativas de hombres y mujeres. En otras palabras, si hay 25 rostros masculinos en un grupo de 40, debe haber 25 en el otro también.</li>
	</ol>
	</li>
	<li>El programa de exposición incidental<ol>
		<li>La primera parte del experimento consiste en exponer por cierto un participante a un conjunto de 40 caras a través de una tarea de la cubierta.</li>
		<li>El experimento comienza con una pantalla 'Listo'. Presiona la barra espaciadora comienza la exposición.</li>
		<li>Una vez que se presiona la barra espaciadora, cada una de las 40 caras se muestra en un tiempo de 1 s. Después de cada imagen, aparece una pantalla que dice "Hombre, mujer?". (La tarea de la cubierta para el participante es informar si un rostro era masculino o femenino).</li>
		<li>Configurar el programa para avanzar a la siguiente cara después de que el participante o bien presiona la tecla M o F, (correspondiente a hombre y mujer). Figura 1 esquematiza la secuencia de eventos en la fase de exposición del experimento.</li>
		<li>Esta fase del experimento es un total de 40 ensayos: uno para cada cara del conjunto.</li>
	</ol>
	</li>
</ol>
<img alt="Figure 1" src="/files/ftp_upload/10209/10209fig1.jpg"> 
Figura 1. Métodos para un paradigma incidental de memoria codificación diseñada para demostrar el efecto de cara invertida. El experimento consta de dos partes. En la primera parte, llamada la fase de codificación de daños incidentales, los participantes observar un conjunto de 40 caras, uno por uno y se pidieron que informe simplemente si cada cara es de hombre o mujer. En la segunda fase, el participante se da una prueba de memoria de la sorpresa. En cada ensayo, dos caras se muestran al lado. Uno de cada par es una de las caras que se muestra en la fase de codificación, y el otro, llamado la hoja, es una cara nueva, nunca antes vista por el observador. La tarea es usar las teclas de flecha izquierda y derecha para indicar que se enfrentan en cada par es el visto anteriormente. Crucial, la mitad de los pares de cara aparecen boca abajo. La medida de interés depende de exactitud de informe para el lado derecho en comparación con las caras boca abajo. <a href="https://www.jove.com/files/ftp_upload/10209/10209fig1large.jpg" target="_blank">Haga clic aquí para ver una versión más grande de esta figura.</a>
<ol start="3">
	<li>El programa de la fase de prueba<ol>
		<li>La parte de prueba del experimento también incluye 40 ensayos.</li>
		<li>Para cada ensayo, seleccione al azar una de las caras viejas y una de las caras previamente reservadas (del mismo sexo). Coloque uno en el lado izquierdo de la pantalla y otro a la derecha.</li>
		<li>La tarea es para que el participante indicar con la tecla de flecha izquierda o derecha cuál de las caras en un par fue vista antes.</li>
		<li>La manipulación fundamental es que en medio de los ensayos, las dos caras se presentan al revés.</li>
		<li>Combinación al azar ensayos al revés y derecho-lado-para arriba.</li>
	</ol>
	</li>
</ol>
3. ejecución del experimento
<ol>
	<li>Antes de empezar el experimento, es una buena idea pedirle al participante si él o ella tiene conocidos impedimentos visuales o dificultades y en particular, si piensan que tienen alguna dificultad para reconocer personas.</li>
	<li>Asiento a 60 cm del monitor de la computadora presentación participante.</li>
	<li>Explicar la fase de codificación al participante siguiente, sin mencionar la fase de prueba para venir:<ol>
		<li>"Se trata de un experimento sobre percepción de la cara. En cada ensayo, verá una cara solo por un segundo, seguido por una pantalla en la que se le pedirá identificar el sexo de la cara que acabas de ver. Pulse la tecla M para masculino y la tecla F para mujer. La tarea puede parecer muy fácil, como estamos llevando a cabo un estudio con varios experimentos, algunos estímulos incluyendo fácil identificar y algunas con estímulos alterado digitalmente, más desafiantes. Los resultados, tomados en conjunto, nos ayudará a entender las características faciales usadas para reconocer el sexo de una cara. Si parece fácil o difícil para usted, por favor, haz tu mejor esfuerzo. Sólo hay 40 ensayos y tardará menos de cinco minutos".</li>
	</ol>
	</li>
	<li>Inicio del programa y soporte cerca como el participante termina esta fase del experimento.</li>
	<li>Cuando el participante se hace, decir lo siguiente:<ol>
		<li>"Gracias por completar la parte del estudio. Gustaría que ahora hacer un segundo experimento, que también va a durar sólo cinco minutos. En cada ensayo, usted verá dos caras, una en el lado izquierdo de la pantalla y una lado derecho. Una de las caras de cada par será uno de los rostros que acabas de ver, y el otro será una nueva cara, uno que no aparece en la tarea de juicio sólo hizo. Su tarea es ahora identificar la cara de 'vieja', que apareció en la tarea de juicio. Utilice la tecla flecha izquierda para indicar la cara de la izquierda y la tecla de flecha derecha para el rostro a la derecha. En algunos de los ensayos, las dos caras se muestran invertida. Esto es irrelevante, su tarea es siempre hacer todo lo posible para identificar la cara que crees que vio una vez ya. "</li>
		<li>Soporte como el participante completa la prueba de memoria.</li>
	</ol>
	</li>
</ol>

El descubrimiento de que invertido caras son difíciles de proceso tiene muchas aplicaciones. Estudios de neuroimagen, por ejemplo, han aprovechado el efecto para identificar las regiones del cerebro implicadas en procesamiento especializado de la cara. Las exploraciones del cerebro se toman cuando observadores Ve el derecho como invierten caras. A continuación se comparan las respuestas a las dos clases de estímulos. Ambos conjuntos de estímulos tienen propiedades visuales muy similares en general, una actividad similar ...

el efecto de cara invertida

Fuente: Laboratorio de Jonathan Flombaum, Johns Hopkins University
En la percepción, es a menudo el caso que la capacidad de reconocer e interpretar estímulos complejos sin esfuerzo pero realmente las demandas complicadas e intensivo tratamiento. Esto es porque el proceso es especializado y automatizado para ciertos tipos de estímulos muy importantes. Entre los mejores ejemplos de este fenómeno es el proceso de la cara. No tratan de detectar y reconocer caras. Parece suceder. Sin embargo, detección de caras y decirles aparte de uno a otro es realmente una tarea computacional exigente.

Habilidades de reconocimiento facial humano dependen de cálculos especializados y redes cerebrales dedicados. Una simple demostración de esto es el efecto de cara invertida. Reconociendo caras al revés es mucho más difícil que reconocerlos hacia arriba, pero el mismo no es cierto para muchas otras clases de objetos visuales. El efecto de cara invertida es demostrado en una variedad de maneras. Este video muestra un incidental codificación paradigma de memoria para investigar el procesamiento facial y el efecto de cara invertida.

Para analizar los resultados, simplemente calcular la proporción de caras correctamente identificadas por los participantes en ensayos con revés (invertida) y con las caras hacia arriba (vertical). Comparan el rendimiento usando un gráfico de barras, como se muestra en la figura 2. Para los observadores más visualmente normales, exactitud será mucho mayor con respecto a invertir caras en posición vertical. Sin embargo, esta es una tarea difícil, y puede encontrar desempeño por debajo de 0.9 para caras ve...

El efecto de cara invertida

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
In perception, it is often the case that the ability to recognize and interpret ...

No tratamos de detectar y reconocer rostros, simplemente sucede, por cierto. Sorprendentemente, para un reconocimiento exitoso, los cálculos complejos y exigentes deben ocurrir en redes cerebrales dedicadas para integrar características separadas en una cara cohesiva. Si bien reconocer las caras al revés es relativamente fácil, identificarlas en una posición invertida es mucho más difícil, aunque esto no es cierto para otros tipos de objetos visuales. Esto a menudo se conoce como el efecto de la cara invertida, y se utiliza en experimentos diseñados para investigar cómo se lleva a cabo el reconocimiento facial tanto cognitivamente como en el cerebro. Este video demostrará cómo diseñar y ejecutar, así como cómo analizar e interpretar un experimento que investiga el efecto de la cara invertida a través de un paradigma de memoria de codificación incidental. En este experimento, se les pide a los participantes que juzguen los rostros masculinos y femeninos en dos fases diferentes: exposición incidental y pruebas. Durante la primera parte de exposición incidental, al participante se le muestra un conjunto de 40 caras, una a la vez durante 1 s cada una. Después de que se muestra cada imagen, se le pide al participante que informe si era hombre o mujer presionando una tecla asociada. Este proceso imita nuestra capacidad natural de procesar rostros, incidentalmente, sin saberlo. Luego, para la segunda fase de prueba, se muestran al participante dos caras una al lado de la otra. Uno se elige al azar de la parte de exposición incidental y el otro, llamado papel de aluminio, es del sexo y nunca antes visto por el participante. Las caras en el período de prueba también se entremezclan aleatoriamente, con la mitad de ellas al revés y la otra mitad, al derecho hacia arriba. Se le pide al participante que indique cuál de los dos fue visto anteriormente. En este caso, la variable dependiente es el número de caras correctamente identificadas, una medida simple de la precisión de la memoria, en orientaciones verticales e invertidas. Se espera que los participantes se desempeñen mejor al recordar rostros vistos anteriormente cuando se muestran en posición vertical, en lugar de invertidos. El mal rendimiento al identificar las caras invertidas se conoce como efecto de cara invertida. Antes de comenzar el experimento, verifique que el participante no tenga ninguna discapacidad visual conocida o dificultad para reconocer a las personas. Para empezar, siéntese el participante a 60 cm del ordenador de presentación. Explique las instrucciones para la fase de exposición incidental sin mencionar la fase de prueba que se avecina. Inicie el programa y párese cerca mientras el participante realiza la primera fase del experimento y completa 40 ensayos en un período de 5 minutos. Tenga en cuenta que ven una sola cara durante 1 s e identifican el sexo de la cara presionando la tecla 'M' para hombres o 'F' para mujeres. Después de la fase inicial, agradezca al participante por completar esta parte del estudio e infórmele de las instrucciones para la siguiente fase de la prueba. Una vez más, inicie el programa y párese cerca mientras completan la segunda fase de memoria de 40 ensayos. En esta parte, tenga en cuenta que el participante presiona la tecla de flecha izquierda o derecha para indicar qué rostro se observó anteriormente. Para analizar los datos, basta con calcular la proporción de rostros identificados correctamente y graficar los resultados de la precisión de la memoria por tipo de ensayo: vertical frente a invertido. Tenga en cuenta que para la mayoría de los participantes visualmente normales, la precisión es mucho mayor al identificar rostros que están erguidos en lugar de invertidos, lo que demuestra el efecto de cara invertida. El bajo rendimiento con los invertidos sugiere que los mecanismos especializados de procesamiento facial están sintonizados para aprovechar el hecho de que casi siempre se experimentan en una orientación vertical. Ahora que está familiarizado con la complejidad involucrada en el procesamiento de caras invertidas, examinemos escenarios de investigación adicionales donde se puede aplicar el efecto. Los estudios de neuroimagen han utilizado el efecto de la cara invertida para identificar las regiones del cerebro involucradas en el procesamiento especializado de la cara. Las caras erguidas producen una respuesta neuronal más fuerte en el área fusiforme de la cara, o FFA, que las invertidas, lo que sugiere que las caras invertidas no logran involucrar a las neuronas especializadas en el procesamiento facial. Además, el daño cerebral a la FFA puede resultar en un trastorno conocido como prosopagnosia, la incapacidad de reconocer rostros, incluido el propio. La tarea se utiliza a menudo para diagnosticar la ceguera facial, ya que las personas prosopagnósticas suelen tener tanta dificultad para identificar las caras del lado derecho como las invertidas. Acabas de ver la introducción de JoVE al efecto de cara invertida. Ahora debería tener una buena comprensión de cómo diseñar y llevar a cabo este tipo de experimento mediante la implementación de la codificación de una serie de caras y la recuperación de caras familiares de memoria. También debes saber analizar e interpretar los resultados. ¡Gracias por mirar!

Education

Educación

JoVE Science Education

Psychology

Psicología

Sensation and Perception

Sensación y percepción

face recognition and upside-down faces

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Face Recognition and Upside-Down Faces

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Explore how the brain processes faces and why upside-down faces are harder to recognize. Learn the inverted-face effect through incidental memory testing.

Face Recognition and Upside-Down Faces | JoVE K12

Jonathan Flombaum

Overview

Experimental Design

Running the Experiment

Representative Results

Applications

Summary

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explant-culture-for-developmental-studies

Explant Culture for Developmental Studies

Explant culture is a technique in which living cells or tissues are removed from an embryo for continued development outside of the organism. This ex vivo ...

DNA Methylation Analysis

Methylation at CpG dinucleotides is a chemical modification of DNA hypothesized to play important roles in regulating gene expression. In particular, the ...

Expression Profiling with Microarrays

Microarrays are important tools for profiling gene expression, and are based on complementary binding between probes that are attached to glass chips and ...

Density Gradient Ultracentrifugation

Density gradient ultracentrifugation is a common technique used to isolate and purify biomolecules and cell structures. This technique exploits the fact ...

F&#246;rster Resonance Energy Transfer (FRET)

F&#246;rster resonance energy transfer (FRET) is a phenomenon used to investigate close-range biochemical interactions. In FRET, a donor photoluminescent ...

detecting-environmental-microorganisms-with-polymerase-chain-reaction

Detecting Environmental Microorganisms with the Polymerase Chain Reaction and Gel Electrophoresis

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - Arizona University
Demonstrating Author: Bradley Schmitz
Polymerase chain reaction (PCR) is ...

Gel Purification

Gel purification is used to recover DNA fragments after electrophoretic separation. DNA recovery from an agarose gel includes three basic steps: binding, ...

Detecting Reactive Oxygen Species

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are ...

Gene Silencing with Morpholinos

Morpholino-mediated gene silencing is a common technique used to study roles of specific genes during development. Morpholinos inhibit gene expression by ...

development-and-reproduction-of-the-laboratory-mouse

Development and Reproduction of the Laboratory Mouse

Successful breeding of the laboratory mouse (Mus musculus) is critical to the establishment and maintenance of a productive animal colony. Additionally, ...

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

HS-LS1-1.

Face Recognition and Upside-Down Faces

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